Hydrophobically associating copolymers

ABSTRACT

Water-soluble, hydrophobically associating copolymers which comprise new types of hydrophobically associating monomers. The monomers comprise an ethylenically unsaturated group and a polyether group with block structure comprising a hydrophilic polyalkylene oxide block which consists essentially of ethylene oxide groups, and a terminal, hydrophobic polyalkylene oxide block which consists of alkylene oxides with at least 4, preferably at least 5 carbon atoms.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of and claims benefit toU.S. patent application Ser. No. 13/680,528, filed Nov. 19, 2012 whichis a divisional application of and claims benefit to U.S. patentapplication Ser. No. 12/783,877, filed May 20, 2010, now issued U.S.Pat. No. 8,362,180 which claims benefit to U.S. Provisional ApplicationNo. 61/179,743, filed May 20, 2009, which are hereby incorporated byreference in their entirety.

The present invention relates to water-soluble, hydrophobicallyassociating copolymers which comprise new types of hydrophobicallyassociating monomers. The monomers comprise an ethylenically unsaturatedgroup and a polyether group with block structure comprising ahydrophilic polyalkylene oxide block, which consists essentially ofethylene oxide groups, and a terminal, hydrophobic polyalkylene oxideblock, which consists of alkylene oxides having at least 4 carbon atoms,preferably at least 5 carbon atoms.

Water-soluble, thickening polymers are used in many areas of technology,for example in the area of cosmetics, in foods, for the production ofcleaners, printing inks, emulsion paints and in the recovery of mineraloil.

Many chemically different classes of polymers are known which can beused as thickeners. An important class of thickening polymers is theso-called hydrophobically associating polymers. This is understood bythe person skilled in the art as meaning water-soluble polymers whichhave lateral or terminal hydrophobic groups, such as, for example,relatively long alkyl chains. In aqueous solution, such hydrophobicgroups can associate with themselves or with other substances havinghydrophobic groups. As a result of this, an associative network isformed, through which the medium is thickened.

EP 705 854 A1, DE 100 37 629 A1 and DE 10 2004 032 304 A1 disclosewater-soluble, hydrophobically associating copolymers and their use, forexample in the construction chemistry sector. The described copolymerscomprise acidic monomers, such as, for example, acrylic acid,vinylsulfonic acid, acrylamidomethylpropanesulfonic acid, basicmonomers, such as acrylamide, dimethylacrylamide, or monomers comprisingcationic groups, such as, for example, monomers having ammonium groups.Monomers of this type impart water solubility to the polymers. Ashydrophobically associating monomers, the disclosed copolymers in eachcase comprise monomers of the following type:H₂C═C(R^(x))—COO—(—CH₂—CH₂—O—)_(q)—R^(y) or elseH₂C═C(R^(x))—O—(—CH₂—CH₂—O—)_(q)—R^(y)), where R^(x) is typically H orCH₃ and R^(y) is a relatively large hydrocarbon radical, typicallyhydrocarbon radicals having 8 to 40 carbon atoms. Relatively long alkylgroups or else a tristyrylphenyl group are mentioned, for example, inthe specifications.

A further important class of hydrophobically associating copolymers arealkali-soluble dispersions, as are disclosed, for example, by EP 13 836A1 or WO 2009/019225. Dispersions of this type comprise on the one handacidic monomers, in particular acrylic acid, the already mentionedhydrophobically associating monomers and also nonhydrophilic monomers,such as, for example, alkyl acrylates. Copolymers of this type arepresent in the acidic pH range as dispersion, but form a solution in thealkaline pH range and thus develop their thickening effect.

Polymers which have polyethylene oxide blocks, blocks of higher alkyleneoxides and additionally ethylenically unsaturated groups are also knownfrom other areas of technology.

WO 2004/044035 A1 discloses polyoxyalkylene block copolymers with ablock comprising polystyrene oxide which can be used as emulsifiers forthe preparation of dispersions. The examples disclose compounds in whichallyl alcohol or hydroxybutyl vinyl ether is firstly provided with apolystyrene oxide group and then with a polyethylene oxide group asterminal group. The terminal group can optionally also be furtherfunctionalized, for example with acid groups. The described blockcopolymer is used for the preparation of styrene-acrylate dispersions.

WO 2004/026468 A1 discloses block copolymers comprising an alkyleneoxide block, a block of glycidyl ethers and also an alkylene oxideblock, where the block copolymers have an ethylenically unsaturated headgroup. The terminal group can additionally be functionalized with acidgroups. The block copolymers are used as polymerizable emulsifiers. Theuse for the preparation of water-soluble, hydrophobically associatingcopolymers is not mentioned.

EP 1 069 139 A2 discloses aqueous dispersions which are obtained bypolymerization of ethylenically unsaturated water-insoluble compounds inthe presence of a water-soluble allyl or vinyl ether. The allyl or vinylethers have a polyalkylene oxide group which is formed fromC₂-C₄-alkylene oxides, where ethylene oxide units must obligatorily bepresent. The alkylene oxide units can be arranged randomly or blockwise,and the polyalkylene oxide group can have H or a C₁ to C₄ group asterminal group. The examples specifically mention polyethyleneoxide-b-polypropylene oxide-monobutyl vinyl ether.

JP 2001-199751 A discloses the preparation of a dispersant for cement.Here, maleic anhydride is copolymerized with a macromonomer. Themacromonomer is a polyoxyalkylene block copolymer comprising apolyethylene oxide block and a block of an alkylene oxide selected fromthe group of propylene oxide, butylene oxide or styrene oxide, theterminal OH groups being etherified with a C₂- to C₅-alkenyl group orwith a C₁-C₅-alkyl group.

JP 2000-119699 A discloses a deinking auxiliary in the reprocessing ofwastepaper. For this, a polyoxyalkylene block copolymer is used whichhas a terminal C₈- to C₂₄-alkyl or alkenyl group which is joined to anethylene oxide-propylene oxide block, a polyethylene oxide block andalso a block comprising propylene oxide or higher alkylene oxides. Thepreparation of polymers starting from this block copolymer is notdescribed.

It is known to use hydrophobically associating copolymers in the fieldof mineral oil recovery, in particular for enhanced oil recovery (EOR).Details on using hydrophobically associating copolymers for enhanced oilrecovery are described, for example, in the overview article by Taylor,K. C. and Nasr-El-Din, H. A. in J. Petr. Sci. Eng. 1998, 19, 265-280.

The techniques of enhanced oil recovery include “polymer flooding”. Amineral oil deposit is not a subterranean “sea of mineral oil”, but themineral oil is held in the tiny pores of the mineral oil-conveying rock.The diameter of the cavities in the formation is usually only a fewmicrometers. For the polymer flooding, an aqueous solution of athickening polymer is injected into a mineral oil deposit throughinjection bores. By injecting in the polymer solution, the mineral oilis forced through said cavities in the formation starting from theinjection bore in the direction of the production bore, and the mineraloil is recovered via the production bore. It is important for thisapplication that the aqueous polymer solution contains no gel particlesat all. Even small gel particles with dimensions in the micrometer rangecan block the fine pores in the formation and thus bring the mineral oilrecovery to a standstill. Hydrophobically associating copolymers forenhanced oil recovery should therefore have the lowest possible fractionof gel particles.

The aforementioned monomers H₂C═C(R^(x))—COO—(—CH₂—CH₂—O—)_(q)—R^(y) andH₂C═C(R^(x))—O—(—CH₂—CH₂—O—)_(q)—R^(y) are usually prepared by means ofa two-stage process. In a first stage, an alcohol R—OH is ethoxylated,giving an ethoxylated alcohol of the general formulaHO—(—CH₂—CH₂—O—)_(q)—R^(y). This can be reacted in a second stage with(meth)acrylic anhydride or acetylene to give the specified monomers. Asa by-product of the first stage (i.e. of the ethoxylation of thealcohol), polyethylene oxide HO—(—CH₂—CH₂—O)_(q)—H is formed in smallamounts. In the second stage, the difunctional moleculesH₂C═C(R^(x))—COO—(—CH₂—CH₂—O—)_(q)—OC—C(R^(x))═CH₂ orH₂C═C(R^(x))—O—(—CH₂—CH₂—O—)_(q)—C(R^(x))═CH₂ can be formed therefrom.Since purification is extremely complex, these by-products are usuallynot separated off. Difunctional molecules of this type have acrosslinking effect and consequently lead in the course of apolymerization to the formation of crosslinked products. As a result ofthis, the formed polymers automatically have certain gel fractions whichare extremely troublesome when using the polymers for EOR. Furthermore,for reasons of cost, it is in any case desirable to provide the simplestpossible method for the preparation of the monomers.

It was therefore an object of the invention to provide hydrophobicallyassociating copolymers with low gel fractions. Furthermore, thecopolymers should be able to be prepared more economically thanhitherto.

Correspondingly, water-soluble, hydrophobically associating copolymershave been found which comprise at least the following monomers:

-   -   (a) 0.1 to 20% by weight of at least one monoethylenically        unsaturated, hydrophobically associating monomer (a), and    -   (b) 25% by weight to 99.9% by weight of at least one        monoethylenically unsaturated hydrophilic monomer (b) different        therefrom,    -   where the quantitative data are based in each case on the total        amount of all of the monomers in the copolymer, and where at        least one of the monomers (a) is a monomer of the general        formula (I)        H₂C═C(R¹)—R⁴—O—(—CH₂—CH(R²)—O—)_(k)—(—CH₂—CH(R³)—O—)_(l)—R⁵  (I)    -   where the units —(—CH₂—CH(R²)—O—)_(k) and —(—CH₂—CH(R³)—O—)_(l)        are arranged in block structure in the order shown in        formula (I) and the radicals and indices have the following        meaning:    -   k: a number from 10 to 150,    -   l: a number from 5 to 25,    -   R¹: H or methyl,    -   R²: independently of one another, H, methyl or ethyl, with the        proviso that at least 50 mol % of the radicals R² are H,    -   R³: independently of one another, a hydrocarbon radical having        at least 2 carbon atoms or an ether group of the general formula        —CH₂—O—R^(3′), where R^(3′) is a hydrocarbon radical having at        least 2 carbon atoms,    -   R⁴: a single bond or a divalent linking group selected from the        group of —(C_(n)H_(2n))—[R^(4a)], —O—(C_(n′)H_(2n′))—[R^(4b)]        and —C(O)—O—(C_(n″)H_(2n″))—[R^(4c)], where n, n′ and n″ is in        each case a natural number from 1 to 6,    -   R⁵: H or a hydrocarbon radical having 1 to 30 carbon atoms.

Furthermore, the use of such copolymers for the development,exploitation and completion of subterranean mineral oil deposits andnatural gas deposits, as additive for aqueous construction systems whichcomprise hydraulic binder systems and for the production of liquiddetergents and cleaners has been found, as well as compositions of thecopolymers preferred for the respective use.

Regarding the invention, the details are as follows:

The hydrophobically associating copolymers according to the inventionare water-soluble copolymers which have hydrophobic groups. In aqueoussolution, the hydrophobic groups are able to associate with themselvesor with substances having other hydrophobic groups and, through thisinteraction, thicken the aqueous medium.

It is known to the person skilled in the art that the solubility ofhydrophobically associating (co)polymers in water can be more or lessdependent on the pH depending on the type of monomers used. A referencepoint for assessing the solubility in water should in each casetherefore be the pH desired for the respective intended use of thecopolymer. A copolymer which, at a certain pH, has an inadequatesolubility for the intended use may have an adequate solubility at adifferent pH. The term “water-soluble” encompasses in particular alsoalkali-soluble dispersions of polymers, i.e. polymers which are presentin the acidic pH range as dispersions and dissolve in water and developtheir thickening effect only in the alkaline pH range.

In an ideal case, the copolymers according to the invention should bemiscible with water in any desired ratio. According to the invention,however, it is sufficient if the copolymers are water-soluble at leastat the desired use concentration and at the desired pH. As a rule, thesolubility in water at room temperature should be at least 20 g/l,preferably at least 50 g/l and particularly preferably at least 100 g/l.

Besides the hydrophobic groups already mentioned, the hydrophobicallyassociating copolymers according to the invention therefore comprisehydrophilic groups in an amount such that the described water solubilityis ensured at least in the pH range intended for the respectiveapplication.

Monomer (a)

The hydrophobically associating copolymer according to the inventioncomprises at least one monoethylenically unsaturated monomer (a) whichimparts hydrophobically associating properties to the copolymeraccording to the invention and is therefore referred to below ashydrophobically associating monomer.

Monomer (a) of the Formula (I)

According to the invention, at least one of the monoethylenicallyunsaturated monomers (a) is a monomer of the general formulaH₂C═C(R¹)—R⁴—O—(—CH₂—CH(R²)—O—)_(k)—(—CH₂—CH(R³)—O)_(l)—R⁵  (I).

In the monomers (a) of the formula (I), an ethylenic group H₂C═C(R¹)— isbonded via a divalent, linking group —R⁴—O— to a polyoxyalkylene radicalwith block structure —(—CH₂—CH(R²)—O—)_(k)—(—CH₂—CH(R³)—O—)_(l)—R⁵ wherethe two blocks —(—CH₂—CH(R²)—O—)_(k) and —(—CH₂—CH(R³)—O—)_(l) arearranged in the order shown in formula (I). The polyoxyalkylene radicalhas either a terminal OH group or a terminal ether group —OR⁵.

In the aforementioned formula, R¹ is H or a methyl group.

R⁴ is a single bond or a divalent, linking group, selected from thegroup of —(C_(n)H_(2n))-[group R^(4a)], —O—(C_(n′)H_(2n′))-[groupR^(4a)]— and —C(O)—O—(C_(n″)H_(2n″))-[group R^(4c)]. In the specifiedformulae, n, n′ and n″ are in each case a natural number from 1 to 6. Inother words, the linking group is straight-chain or branched aliphatichydrocarbon groups having 1 to 6 hydrocarbon atoms which are linked tothe ethylenic group H₂C═C(R¹)— either directly, via an ether group —O—or via an ester group —C(O)—O—. The groups —(C_(n)H_(2n))—,—(C_(n′)H_(2n′))— and —(C_(n″)H_(2n″))— are preferably linear aliphatichydrocarbon groups.

Preferably, the group R^(4a) is a group selected from —CH₂—, —CH₂—CH₂—and —CH₂—CH₂—CH₂—, and is particularly preferably a methylene group—CH₂—.

Preferably, the group R^(4b) is a group selected from —O—CH₂—CH₂—,—O—CH₂—CH₂—CH₂— and —O—CH₂—CH₂—CH₂—CH₂—, and is particularly preferably—O—CH₂—CH₂—CH₂—CH₂—.

Preferably, the group R^(4c) is a group selected from —C(O)—O—CH₂—CH₂—,—C(O)O—CH(CH₃)—CH₂—, —C(O)O—CH₂—CH(CH₃)—, —C(O)O—CH₂—CH₂—CH₂—CH₂— and—C(O)O—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—, particular preference being given to—C(O)—O—CH₂—CH₂— and —C(O)O—CH₂—CH₂—CH₂—CH₂— and very particularpreference being given to —C(O)—O—CH₂—CH₂—.

The group R⁴ is particularly preferably a group R^(4a) or R^(4b),particularly preferably a group R^(4b).

Furthermore, R⁴ is particularly preferably a group selected from —CH₂—or —O—CH₂—CH₂—CH₂—CH₂—, and is very particularly preferably—O—CH₂—CH₂—CH₂—CH₂—.

Furthermore, the monomers (I) have a polyoxyalkylene radical whichconsists of the units —(—CH₂—CH(R²)—O—)_(k) and —(—CH₂—CH(R³)—O—)_(l),where the units are arranged in block structure in the order shown informula (I). The transition between the two blocks may be abrupt orcontinuous.

In the block —(—CH₂—CH(R²)—O—)_(k), the radicals R², independently ofone another, are H, methyl or ethyl, preferably H or methyl, with theproviso that at least 50 mol % of the radicals R² are H. Preferably, atleast 75 mol % of the radicals R² are H, particularly preferably atleast 90 mol % and very particularly preferably exclusively H. In thespecified block, a polyoxyethylene block which can optionally still havecertain fractions of propylene oxide and/or butylene oxide units is thuspreferably a pure polyoxyethylene block.

The number of alkylene oxide units k is a number from 10 to 150,preferably 12 to 100, particularly preferably 15 to 80, veryparticularly preferably 20 to 30 and for example ca. 22 to 25. For theperson skilled in the art in the field of polyalkylene oxides, it isclear that the specified numbers are average values of distributions.

In the second, terminal block —(—CH₂—CH(R³)—O)_(l)—, the radicals R³,independently of one another, are hydrocarbon radicals of at least 2carbon atoms, preferably, at least 3 and particularly preferably 3 to 10carbon atoms. These may be an aliphatic and/or aromatic, linear orbranched carbon radical. These are preferably aliphatic radicals.

Examples of suitable radicals R³ comprise ethyl, n-propyl, n-butyl,n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl or n-decyl and alsophenyl. Examples of preferred radicals comprise n-propyl, n-butyl,n-pentyl and particular preference is given to an n-propyl radical.

The radicals R³ may also be ether groups of the general formula—CH₂—O—R^(3′), where R^(3′) is an aliphatic and/or aromatic, linear orbranched hydrocarbon radical having at least 2 carbon atoms, preferablyat least 3 and particularly preferably 3 to 10 carbon atoms. Examples ofradicals R^(3′) comprise n-propyl, n-butyl, n-pentyl, n-hexyl,2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or phenyl.

The block —(—CH₂—CH(R³)—O—)_(l)— is thus a block which consists ofalkylene oxide units having at least 4 carbon atoms, preferably at least5 carbon atoms, and/or glycidyl ethers with an ether group of at least2, preferably at least 3 carbon atoms. Preferably, the radicals R³ arethe specified hydrocarbon radicals; the building blocks of the secondterminal block are particularly preferably alkylene oxide unitscomprising at least 5 carbon atoms, such as pentene oxide units or unitsof higher alkylene oxides.

The number of alkylene oxide units l is a number from 5 to 25,preferably 6 to 20, particularly preferably 8 to 18, very particularlypreferably 10 to 15 and for example ca. 12.

The radical R⁵ is H or a preferably aliphatic hydrocarbon radical having1 to 30 carbon atoms, preferably 1 to 10 and particularly preferably 1to 5 carbon atoms. Preferably, R⁵ is H, methyl or ethyl, particularlypreferably H or methyl and very particularly preferably H.

In the monomers of the formula (I), a terminal, monoethylenic group isthus linked to a polyoxyalkylene group with block structure, andspecifically firstly to a hydrophilic block having polyethylene oxideunits and this in turn to a second terminal, hydrophobic block which iscomposed at least of butene oxide units, preferably at least penteneoxide units or units of higher alkylene oxides, such as, for example,dodecene oxide. The second block has a terminal —OR⁵ group, inparticular an OH group. In contrast to the hydrophobically associatingcopolymers known from the prior art, the end group does not have to beetherified with a hydrocarbon radical for the hydrophobic association,but the terminal block —(—CH₂—CH(R³)—O—)_(l) itself with the radicals R³is responsible for the hydrophobic association of the copolymersprepared using the monomers (a). The etherification is only one optionwhich can be selected by the person skilled in the art depending on thedesired properties of the copolymer.

For the person skilled in the art in the field of polyalkylene oxideblock copolymers, it is clear that the transition between the two blockscan be abrupt or continuous depending on the type of preparation. In thecase of a continuous transition, between the two blocks, there is also atransition zone which comprises monomers of the two blocks. If the blocklimit is fixed in the middle of the transition zone, correspondingly thefirst block —(—CH₂—CH(R²)—O—)_(k) can still have small amounts of units—CH₂—CH(R³)—O— and the second block —(—CH₂—CH(R³)—O—)_(l) can have smallamounts of units —CH₂—CH(R²)—O—, although these units are notdistributed randomly over the block, but are arranged in said transitionzone.

Preparation of the Monomers (a) of the Formula (I)

The preparation of the hydrophobically associating monomers (a) of theformula (I) can take place in accordance with methods known in principleto the person skilled in the art.

In one preferred preparation process the preparation of the monomers (a)starts from suitable monoethylenically unsaturated alcohols (III) whichare then alkoxylated in a two-stage process, so that the block structurementioned is obtained. Monomers (a) of the formula (I) where R⁵=H areobtained. The latter may optionally be etherified in a further processstep.

The type of ethylenically unsaturated alcohols (III) to be used isgoverned here in particular by the group R⁴.

If R⁴ is a single bond, the starting materials are alcohols (III) of thegeneral formula H₂C═C(R¹)—O—(—CH₂—CH(R^(2′))—O—)_(d)—H (IIIa), where R¹has the meaning defined above, R^(2′) is H and/or CH₃, preferably H andd is a number from 1 to 5, preferably 1 or 2. Examples of such alcoholscomprise diethylene glycol vinyl ether H₂C═CH—O—CH₂—CH₂—O—CH₂—CH₂—OH ordipropylene glycol vinyl ether H₂C═CH—O—CH₂—CH(CH₃)—O—CH₂—CH(CH₃)—OH,preference being given to diethylene glycol vinyl ether.

For the preparation of monomers (a) in which R⁴ is not a single bond, itis possible to use alcohols of the general formula H₂C═C(R¹)—R⁴—OH(IIIa) or even alcohols having alkoxy groups of the formulaH₂C═C(R¹)—R⁴—O—(—CH₂—CH(R^(2′))—O—)_(d)—H (IIIb), where R^(2′) and dhave the meaning defined above, and R⁴ is in each case selected from thegroup R^(4a), R^(4b) and R^(4c).

For the preparation of the monomers with linking group R^(4a),preference is given to starting from alcohols of the formulaH₂C═C(R¹)—(C_(n)H_(2n))—OH, in particular H₂C═CH—(C_(n)H_(2n))—OH oralcohols of the formula H₂C═C(R¹)—O—(—CH₂—CH(R²)—O—)_(d)—H, inparticular those where R¹=H and R²=H and/or CH₃. Examples of preferredalcohols comprise allyl alcohol H₂C═CH—CH₂—OH or isoprenolH₂C═C(CH₃)—CH₂—CH₂—OH.

For the preparation of the monomers with linking group R^(4b), thestarting materials are vinyl ethers of the formulaH₂C═C(R¹)—O—(C_(n′)H_(2n′))—OH, preferably H₂C═CH—O—(C_(n′)H_(2n′))—OH.Particularly preferably, ω-hydroxybutyl vinyl etherH₂C═CH—O—CH₂—CH₂—CH₂—CH₂—OH can be used.

For the preparation of the monomers with linking group R^(4c), thestarting materials are hydroxyalkyl(meth)acrylates of the generalformula H₂C═C(R¹)—C(O)—O—(C_(n″)H_(2n″))—OH, preferablyH₂C═C(R¹)—C(O)—O—(C_(n″)H_(2n″))—OH. Examples of preferredhydroxyalkyl(meth)acrylates comprise hydroxyethyl(meth)acrylateH₂C═C(R¹)—C(O)—O—CH₂—CH₂—OH and also hydroxybutyl(meth)acrylateH₂C═C(R¹)—C(O)—O—CH₂—CH₂—CH₂—CH₂—OH.

The specified starting compounds are alkoxylated, and specifically in atwo-stage process firstly with ethylene oxide, optionally in a mixturewith propylene oxide and/or butylene oxide and in a second step withalkylene oxides of the general formulae (Xa) or (Xb)

where R³ in (Xa) or R^(3′) in (Xb) has the meaning defined at theoutset.

The procedure for an alkoxylation including the preparation of blockcopolymers from various alkylene oxides is known in principle to theperson skilled in the art. It is likewise known to the person skilled inthe art that it is possible to influence via the reaction conditions, inparticular the choice of catalyst, the molecular weight distribution ofthe alkoxylates and the orientation of alkylene oxide units in apolyether chain.

The alkoxylates can be prepared, for example, by base catalyzedalkoxylation. For this, the alcohol used as starting material can beadmixed in a pressurized reactor with alkali metal hydroxides,preferably potassium hydroxide, or with alcohol metal alcoholates, suchas, for example, sodium methylate. Through a reduced pressure (forexample <100 mbar) and/or elevation of the temperature (30 to 150° C.),water still present in the mixture can be stripped off. The alcohol isthen in the form of the corresponding alcoholate. The system is thenrendered inert with inert gas (e.g. nitrogen) and in a first step,ethylene oxide, optionally in the mixture with propylene oxide and/orbutylene oxide, is added stepwise at temperatures of from 60 to 180° C.,preferably 130 to 150°. The addition takes place typically over thecourse of 2 to 5 hours without the invention being limited thereto. Whenthe addition is complete, the reaction mixture is expediently left toafter-react, for example for ½ h to 1 h. In a second step, the alkyleneoxides having at least 5 carbon atoms are then metered in stepwise. Thereaction temperature in the second stage can be maintained or elsealtered. A ca. 10 to 25° C. lower reaction temperature than in the firststage has proven useful.

The alkoxylation can also be carried out using techniques which lead tonarrower molecular weight distributions than in the case of thebase-catalyzed synthesis. For this, double hydroxide clays as describedin DE 43 25 237 A1, for example, can be used as catalyst. Thealkoxylation can particularly preferably take place using double metalcyanide catalysts (DMC catalysts). Suitable DMC catalysts are disclosed,for example, in DE 102 43 361 A1, in particular sections [0029] to[0041] and the literature cited therein. For example, catalysts of theZn—Co type can be used. To carry out the reaction, the alcohol used asstarting material can be admixed with the catalyst, the mixturedewatered as described above and reacted with the alkylene oxides asdescribed. Usually, not more than 250 ppm of catalyst with regard to themixture are used, and, on account of this small amount, the catalyst canremain in the product.

The alkoxylation can furthermore also be carried out with acidcatalysis. The acids may be Brönstedt acids or Lewis acids. To carry outthe reaction, the alcohol used as starting material can be admixed withthe catalyst, the mixture can be dewatered as described above andreacted with the alkylene oxides as described. At the end of thereaction, the acidic catalyst can be neutralized by adding a base, forexample KOH or NaOH, and, if required, filtered off.

For the person skilled in the art in the field of polyalkylene oxides,it is clear that the orientation of the hydrocarbon radicals R³ and, ifappropriate, R² can depend on the conditions during the alkoxylation,for example on the catalyst selected for the alkoxylation. The alkyleneoxide groups can thus be incorporated into the monomer either in theorientation —(—CH₂—CH(R³)—O—) or else in inverse orientation—(—CH(R³)—CH₂—O—)—. The depiction in formula (I) should therefore not beregarded as limited to a certain orientation of the groups R² and/or R³.

If the monomers (a) of the formula (I) with a terminal OH group (i.e.R⁵=H) obtained as described are to be optionally etherified, this cantake place with customary alkylating agents known in principle to theperson skilled in the art, for example alkyl sulfates. For theetherification, in particular dimethyl sulfate or diethyl sulfate can beused.

The described preferred preparation process for the monomers (I) alsodiffers, including in cases when R⁵ is not H, fundamentally from thesynthesis of known hydrophobically associating monomers by the series ofsynthesis steps: whereas in the case of the synthesis processes for thesynthesis of the known hydrophobically associating monomers mentioned atthe outset, the starting material used is an alcohol, which isalkoxylated and only at the end is a compound with an ethylenicallyunsaturated group reacted with the alkoxylated alcohol, in the case ofthe synthesis variant described according to the invention, theprocedure is reversed: starting material is an ethylenically unsaturatedcompound which is alkoxylated and can then be optionally etherified.This prevents the formation of crosslinking by-products, meaning thatthe preparation of copolymers with a particularly low gel fraction ispossible.

Further Monomers (a)

Besides the monomers (I), it is also possible optionally to usemonoethylenic, hydrophobically associating monomers (a) different fromthe monomers (I). Further monomers (a) have the general formulaH₂C═C(R¹)—Y—Z, where R¹ is H or methyl, Z is a terminal hydrophobicgroup and Y is a linking hydrophilic group. The person skilled in theart is aware of such monomers and makes a suitable selection asappropriate. Examples of such monomers comprise in particular monomersof the general formula H₂C═C(R¹)—COO—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIa) orH₂C═C(R¹)—O—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIb), where q is a number from 10to 150, preferably 12 to 100, particularly preferably 15 to 80, veryparticularly preferably 20 to 30 and for example ca. 25, R¹ is asdefined above and the radicals R⁶, independently of one another, are H,methyl or ethyl, preferably H or methyl, with the proviso that at least50 mol % of the radicals R⁶ are H. Preferably, at least 75 mol % of theradicals R⁶ are H, particularly preferably at least 90 mol % and veryparticularly preferably exclusively H. The radical R⁷ is an aliphaticand/or aromatic, straight-chain or branched hydrocarbon radical havingat least 6 carbon atoms, in particular 6 to 40 carbon atoms, preferably8 to 30 carbon atoms. Examples comprise n-alkyl groups, such as n-octyl,n-decyl or n-dodecyl groups, phenyl groups, and in particularsubstituted phenyl groups. The substituents on the phenyl groups may bealkyl groups, for example C₁- to C₆-alkyl groups, preferably styrylgroups. Particular preference is given to a tristyrylphenyl group. Thespecified hydrophobically associating monomers of the formulae (IIa) and(IIb) are known in principle to the person skilled in the art.

Amounts of the Monomers (a)

The amount of monoethylenically unsaturated, hydrophobically associatingmonomers (a) is governed by the respective intended use of the copolymeraccording to the invention and is generally 0.1 to 20% by weight, basedon the total amount of all of the monomers in the copolymer, preferably0.1 to 12% by weight. In a further preferred embodiment the amount is0.5 to 20% by weight, particularly preferably 0.5 to 12% by weight.

If further monomers (a) are also used besides the monomers (a) of theformula (I), the monomers of the formula (I) should generally be used inan amount of at least 0.1% by weight with regard to the sum of all ofthe monomers in the copolymer, preferably at least 0.5% by weight.Furthermore, the fraction of monomers of the formula (I) shouldgenerally be at least 25% by weight with regard to the amount of all ofthe monomers (a), preferably at least 50% by weight, particularlypreferably at least 75% by weight and particularly preferably onlymonomers of the formula (I) should be used as monomers (a).

Hydrophilic Monomers (b)

Besides the monomers (a), the hydrophobically associating copolymeraccording to the invention comprises at least one monoethylenicallyunsaturated, hydrophilic monomer (b) different therefrom. It is ofcourse also possible to use mixtures of two or more differenthydrophilic monomers (b).

Besides an ethylenic group, the hydrophilic monomers (b) comprise one ormore hydrophilic groups. On account of their hydrophilicity, theseimpart adequate solubility in water to the copolymer according to theinvention. The hydrophilic groups are in particular functional groupswhich comprise O and/or N atoms. They can, moreover, comprise inparticular S and/or P atoms as heteroatoms.

The monomers (b) are particularly preferably miscible with water in anydesired ratio, although it suffices for carrying out the invention thatthe hydrophobically associating copolymer according to the invention hasthe solubility in water mentioned at the start. Generally, thesolubility of the monomers (b) in water at room temperature should be atleast 100 g/l, preferably at least 200 g/l and particularly preferablyat least 500 g/l.

Examples of suitable functional groups comprise carbonyl groups >C═O,ether groups —O—, in particular polyethylene oxide groups—(CH₂—CH₂—O—)_(n)—, where n is preferably a number from 1 to 200,hydroxy groups —OH, ester groups —C(O)O—, primary, secondary or tertiaryamino groups, ammonium groups, amide groups —O(O)—NH—, carboxamidegroups —C(O)—NH₂ or acid groups such as carboxyl groups —COOH, sulfonicacid groups —SO₃H, phosphonic acid groups —PO₃H₂ or phosphoric acidgroups —OP(OH)₃.

Examples of preferred functional groups comprise hydroxy groups —OH,carboxyl groups —COOH, sulfonic acid groups —SO₃H, carboxamide groups—C(O)—NH₂, amide groups —C(O)—NH—, and polyethylene oxide groups—(CH₂—CH₂—O—)_(n)—H, where n is preferably a number from 1 to 200.

The functional groups can be attached directly to the ethylenic group,or else be bonded to the ethylenic group via one or more linkinghydrocarbon groups.

The hydrophilic monomers (b) are preferably monomers of the generalformula H₂C═C(R⁸)R⁹ (III), where R⁸ is H or methyl and R⁹ is ahydrophilic group or a group comprising one or more hydrophilic groups.

The groups R⁹ are groups which comprise heteroatoms in an amount suchthat the solubility in water defined at the start is achieved.

Examples of suitable monomers (b) comprise monomers comprising acidgroups, for example monomers comprising —COOH groups, such as acrylicacid or methacrylic acid, crotonic acid, itatonic acid, maleic acid orfumaric acid, monomers comprising sulfonic acid groups, such asvinylsulfonic acid, allylsulfonic acid,2-acrylamido-2-methylpropanesulfonic acid (AMPS),2-methacrylamido-2-methylpropanesulfonic acid,2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonicacid or 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, or monomerscomprising phosphonic acid groups, such as vinylphosphonic acid,allylphosphonic acid, N-(meth)acrylamidoalkylphosphonic acids or(meth)acryloyloxyalkylphosphonic acids.

Also to be mentioned are acrylamide and methacrylamide and alsoderivatives thereof, such as, for example, N-methyl(meth)acrylamide,N,N′-dimethyl(meth)acrylamide, and N-methylolacrylamide, N-vinylderivatives such as N-vinylformamide, N-vinylacetamide,N-vinylpyrrolidone or N-vinylcaprolactam, and vinyl esters, such asvinyl formate or vinyl acetate. N-vinyl derivatives can be hydrolyzedafter polymerization to vinylamine units, vinyl esters to vinyl alcoholunits.

Further examples comprise monomers comprising hydroxy and/or ethergroups, such as, for example, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, allyl alcohol, hydroxyvinyl ethyl ether,hydroxyl vinyl propyl ether, hydroxyvinyl butyl ether or compounds ofthe formula H₂C═C(R¹)—COO—(—CH₂—CH(R¹⁰)—O—)_(b)—R¹¹ (IVa) orH₂C═C(R¹)—O—(—CH₂—CH(R¹⁰)—O—)_(b)—R¹¹ (IVb), where R¹ is as definedabove and b is a number from 2 to 200, preferably 2 to 100. The radicalsR⁹ are, independently of one another, H, methyl or ethyl, preferably Hor methyl, with the proviso that at least 50 mol % of the radicals R⁹are H. Preferably, at least 75 mol % of the radicals R⁹ are H,particularly preferably at least 90 mol % and very particularlypreferably exclusively H. The radical R¹¹ is H, methyl or ethyl,preferably H or methyl. The individual alkylene oxide units can bearranged randomly or blockwise. In the case of a block copolymer, thetransition between the blocks may be abrupt or gradual.

Suitable hydrophilic monomers (b) are also monomers having ammoniumgroups, in particular ammonium derivatives ofN-(ω-aminoalkyl)(meth)acrylamides or ω-aminoalkyl(meth)acrylic esters.

In particular, the monomers (b) having ammonium groups may be compoundsof the general formulae H₂C═C(R⁸)—CO—NR¹⁴—R¹²—NR¹³ ₃ ⁺X⁻ (Va) and/orH₂C═C(R⁸)—COO—R¹²—NR¹³ ₃ ⁺X⁻ (Vb), where R⁸ has the meaning given above,thus is H or methyl, R¹² is a preferably linear C₁-C₄-alkylene group andR¹⁴ is H or a C₁-C₄-alkyl group, preferably H or methyl. The radicalsR¹³, independently of one another, are C₁-C₄-alkyl, preferably methyl,or a group of the general formula —R¹⁵—SO₃H, where R¹⁵ is a preferablylinear C₁- to C₄-alkylene group or a phenylene group, with the provisothat generally not more than one of the substituents R¹³ is asubstituent having sulfonic acid groups. The three substituents R¹³ areparticularly preferably methyl groups, i.e. the monomer has a group—N(CH₃)₃ ⁺. X⁻ in the above formula is a monovalent anion, for exampleCl⁻. X⁻ can of course also be a corresponding fraction of a polyvalentanion, although this is not preferred. Examples of suitable monomers (b)of the general formula (Va) or (Vb) comprise salts of3-trimethylammonium propylacrylamides or 2-trimethylammoniumethyl(meth)acrylates, for example the corresponding chlorides, such as3-trimethylammonium propylacrylamide chloride (DIMAPAQUAT) and2-trimethylammonium ethyl methacrylate chloride (MADAME-QUAT).

The aforementioned hydrophilic monomers can of course be used not onlyin the depicted acid or base form, but also in the form of correspondingsalts. It is also possible to convert acidic or basic groups intocorresponding salts after the formation of the polymer.

In one preferred embodiment of the invention, the copolymer according tothe invention comprises at least one monomer (b) comprising acid groups.These are preferably monomers which comprise at least one group selectedfrom the group of —COOH, —SO₃H or —PO₃H₂, particular preference beinggiven to monomers comprising COOH groups and/or —SO₃H groups, where theacid groups may also be present completely or partially in the form ofthe corresponding salts.

Preferably, at least one of the monomers (b) is a monomer selected fromthe group of (meth)acrylic acid, vinylsulfonic acid, allylsulfonic acidor 2-acrylamido-2-methylpropanesulfonic acid (AMPS), particularlypreferably acrylic acid and/or APMS or the salts thereof.

The amount of the monomers (b) in the copolymer according to theinvention is 25 to 99.9% by weight, based on the total amount of all ofthe monomers in the copolymer, preferably 25 to 99.5% by weight. Theexact amount is governed by the type and the desired intended use of thehydrophobically associating copolymers and is established accordingly bythe person skilled in the art.

Monomers (c)

Apart from the hydrophilic monomers, the copolymers according to theinvention can optionally comprise monoethylenically unsaturated monomers(c) different from the monomers (a) and (b). It is of course alsopossible to use mixtures of two or more different monomers (c).

The monomers (c) are in particular monomers which essentially havehydrophobic character and are water-soluble only to a small extent.Generally, the solubility of the monomers (c) in water at roomtemperature is less than 100 g/l, preferably less than 50 g/l andparticularly preferably less than 20 g/l.

Examples of such monomers (c) comprise hydrocarbons, in particularstyrene and hydrophobic derivatives, such as, for example,α-methylstyrene or alkylstyrenes, such as 4-methylstyrene or4-ethylstyrene.

Preferably, the further monomers are those of the general formulaH₂C═C(R¹⁶)R¹⁷ (VI), where R¹⁶ is H or methyl and R¹⁷ is a further groupwhich essentially has hydrophobic character.

R¹⁷ is preferably carboxylic acid ester groups —COOR¹⁸, where R¹⁸ is astraight-chain or branched, aliphatic, cycloaliphatic and/or aromatichydrocarbon radical having 1 to 30 carbon atoms, preferably 2 to 12carbon atoms. They are particularly preferably an aliphatic,straight-chain or branched hydrocarbon radical having 2 to 10 carbonatoms.

Examples of such monomers (c) comprise esters of (meth)acrylic acid, forexample alkyl(meth)acrylates, such as methyl(meth)acrylate,ethyl(meth)acrylate, n-propyl(meth)acrylate, n-butyl(meth)acrylate,2-ethylhexyl acrylate or 2-propylheptyl acrylate.

R¹⁶ may also be carboxamide groups —CONHR¹⁷ or —CON(R¹⁷)₂, with theproviso that the number of carbon atoms in the radical R¹⁸ or bothradicals R¹⁸ together is at least 3, preferably at least 4, where thetwo radicals R¹⁸ together may also form a ring. Examples of suchmonomers comprise N-butyl(meth)acrylamide, N-cyclohexyl(meth)acrylamideor N-benzyl(meth)acrylamide.

The monomers (c) also include those monomers which do have hydrophilicgroups besides hydrophobic groups, but in which the hydrophobicmolecular moieties dominate, meaning that the monomers no longer havethe required solubility in water and thus are not alone able to impartthe required solubility to the polymer.

The type and amount of further monomers (c) is governed by the desiredproperties and the intended use of the copolymer and is 0 to 74.9% byweight, based on the total mount of all of the monomers in thecopolymer, preferably 0 to 74.5% by weight.

Monomers (d)

In special cases, besides the monomers (a) and (b) and, if appropriate,(c), the copolymers according to the invention can optionally alsocomprise monomers (d) which have two or more, preferably two,ethylenically unsaturated groups. As a result of this, a certaincrosslinking of the copolymer can be achieved provided that this has noundesired negative effects in the intended use of the copolymer. Anexcessively high degree of crosslinking, however, should in any case beavoided; in particular, the required solubility in water of thecopolymer must not be impaired. Although slight crosslinking may beuseful in individual cases, it is governed by the particular applicationof the copolymer and the person skilled in the art makes an appropriatechoice.

Examples of suitable monomers (d) comprise 1,4-butanedioldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,3-butylene glycoldi(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate or oligoethylene glycol di(meth)acrylates, such as, forexample, polyethylene glycol bis(meth)acrylate,N,N′-methylenebis(meth)acrylamide, ethylene glycol divinyl ether,triethylene glycol divinyl ether, triallylamine, triallylaminemethammonium chloride, tetraallylammonium chloride ortris(2-hydroxy)isocyanurate tri(meth)acrylate.

If present at all, crosslinking monomers (d) are only used in smallamounts. Generally, the amount of the monomers (d) should not exceed 1%by weight with regard to the amount of all of the monomers used.Preferably, not more than 0.5% by weight and particularly preferably notmore than 0.1% by weight should be used. Type and amount of thecrosslinker are established by the person skilled in the art dependingon the desired application of the copolymer.

Preparation of the Hydrophobically Associating Copolymers

The copolymers according to the invention can be prepared by methodsknown in principle to the person skilled in the art by free-radicalpolymerization of the monomers (a) and (b) and optionally (c) and/or(d), for example by bulk polymerization, solution polymerization, gelpolymerization, emulsion polymerization, dispersion polymerization orsuspension polymerization, preferably in aqueous phase.

The synthesis of the monomers (a) of the formula (I) used according tothe invention are particularly preferably prepared by the preparationprocess described above by alkoxylation of alcohols (III), optionallyfollowed by an etherification.

In one preferred embodiment, the preparation is carried out by means ofgel polymerization in aqueous phase, provided all of the monomers usedhave adequate solubility in water. For the gel polymerization, firstly amixture of the monomers, initiators and other auxiliaries is preparedwith water for an aqueous solvent mixture. Suitable aqueous solventmixtures comprise water and water-miscible organic solvents, where thefraction of water is generally at least 50% by weight, preferably atleast 80% by weight and particularly preferably at least 90% by weight.Organic solvents to be mentioned here are in particular water-misciblealcohols such as methanol, ethanol or propanol. Acidic monomers can becompletely or partially neutralized before the polymerization.Preference is given to a pH of ca. 4 to ca. 9. The concentration of allof the components with the exception of the solvents is usually ca. 25to 60% by weight, preferably ca. 30 to 50% by weight.

The mixture is then polymerized photochemically and/or thermally,preferably at −5° C. to 50° C. If thermal polymerization is carried out,preference is given to using polymerization initiators which start evenat a comparatively low temperature, such as, for example, redoxinitiators. The thermal polymerization can be carried out even at roomtemperature or by heating the mixture, preferably to temperatures of notmore than 50° C. The photochemical polymerization is usually carried outat temperatures of from −5 to 10° C. Photochemical and thermalpolymerization can particularly advantageously be combined with oneanother by adding to the mixture both initiators for the thermal andalso for the photochemical polymerization. The polymerization is startedin this case initially photochemically at low temperatures, preferably−5 to +10° C. As a result of the heat of reaction which is liberated,the mixture warms up and as a result of this the thermal polymerizationis additionally started. By means of this combination it is possible toachieve a conversion of more than 99%.

The gel polymerization generally takes place without stirring. It cantake place batchwise by irradiating and/or heating the mixture in asuitable vessel at a layer thickness of from 2 to 20 cm. Thepolymerization produces a solid gel. The polymerization can also becarried out continuously. For this, a polymerization apparatus is usedwhich has a conveyor belt for receiving the mixture to be polymerized.The conveyor belt is equipped with devices for heating or forirradiation with UV radiation. Here, the mixture is poured using asuitable device at one end of the belt, the mixture is polymerized inthe course of transportation in the belt direction and the solid gel canbe removed at the other end of the belt.

After the polymerization, the gel is comminuted and dried. The dryingshould preferably take place at temperatures below 100° C. To avoidsticking together, a suitable separating agent can be used for thisstep. The hydrophobically associating copolymer is obtained as powder.

Further details for carrying out a gel polymerization are disclosed, forexample, in DE 10 2004 032 304 A1, sections [0037] to [0041].

Copolymers according to the invention in the form of alkaline-soluble,aqueous dispersions can preferably be prepared by means of emulsionpolymerization. The procedure for an emulsion polymerization usinghydrophobically associating monomers is disclosed, for example, by WO2009/019225 page 5, line 16 to page 8, line 13.

The copolymers according to the invention preferably have anumber-average molecular weight M_(n) of from 50000 to 20000000 g/mol.

Use of the Hydrophobically Associating Copolymers

The hydrophobically associating copolymers according to the inventioncan be used for thickening aqueous phases.

By selecting the type and amount of the monomers (a) and (b) andoptionally (c) and/or (d) it is possible to adapt the properties of thecopolymers to the particular technical requirements.

The use concentration is established by the person skilled in the artdepending on the type of aqueous phase to be thickened and also on thetype of copolymer. As a rule, the concentration of the copolymer is 0.1to 5% by weight, with regard to the aqueous phase, preferably 0.5 to 3%by weight and particularly preferably 1 to 2% by weight.

The copolymers can be used here on their own or in combination withother thickening components, for example other thickening polymers.Furthermore, they can be formulated for example together withsurfactants to give a thickening system. In aqueous solution, thesurfactants can form micelles and, together with the micelles, thehydrophobically associating copolymers can form a three-dimensional,thickening network.

For use, the copolymer can be dissolved directly in the aqueous phase tobe thickened. It is also conceivable to predissolve the copolymer andthen to add the formed solution to the system to be thickened.

The aqueous phases to be thickened may be, for example, liquid detergentand cleaner formulations, such as, for example, detergents, washingauxiliaries such as, for example, pre-spotters, fabric softeners,cosmetic formulations, pharmaceutical formulations, foods, coatingslips, formulations for the manufacture of textiles, textile printingpastes, printing inks, printing pastes for textile printing, paints,pigment slurries, aqueous formulations for foam generation, deicingmixtures, for example for aircraft, formulations for the constructionindustry, such as, for example, as additive for aqueous constructionsystems based on hydraulic binders such as cement, lime, gypsum andanhydrite and also in water-based paint and coating systems,formulations for the recovery of mineral oil, such as, for example,drilling fluids, formulations for the acidizing or fracturing orformulations for enhanced oil recovery.

Preferred Use and Copolymer (A1) Preferred for this

In one preferred embodiment of the invention, the hydrophobicallyassociating copolymers according to the invention can be used for thedevelopment, exploitation and completion of subterranean mineral oildeposits and natural gas deposits.

The copolymers according to the invention can be used, for example, asadditive to drilling fluids or during well cementing and also inparticular for fracturing.

The copolymers are particularly preferably used for enhanced oilrecovery, and specifically for so-called “polymer flooding”. For this,an aqueous formulation is used which, besides water, comprises at leastone hydrophobically associating copolymer. It is of course also possibleto use mixtures of different copolymers. Moreover, further componentscan of course also be used. Examples of further components comprisebiocides, stabilizers or inhibitors. The formulation can preferably beprepared by initially introducing the water and sprinkling in thecopolymer as powder. The aqueous formulation should be subjected to thesmallest possible shear forces.

The concentration of the copolymer should generally not exceed 5% byweight with regard to the sum of all of the constituents of theformulation and is usually 0.01 to 5% by weight, in particular 0.1 to 5%by weight, preferably 0.5 to 3% by weight and particularly preferably 1to 2% by weight.

The formulation is injected through at least one injection bore into themineral oil deposit, and crude oil is removed from the deposit throughat least one production bore. In this connection, the term “crude oil”is of course intended to mean not only phase-pure oil, but the term alsocomprises the customary crude oil/water emulsions. A deposit isgenerally provided with a plurality of injection bores and with aplurality of production bores. As a result of the pressure generated bythe injected formulation, the so-called “polymer flood”, the mineral oilflows in the direction of the production bore and is recovered via theproduction bore. The viscosity of the flood medium should be adapted asfar as possible to the viscosity of the mineral oil in the mineral oildeposit. The viscosity can be adjusted in particular via theconcentration of the copolymer.

To increase the mineral oil yield, the polymer flooding canadvantageously be combined with other techniques for enhanced oilrecovery.

In one preferred embodiment of the invention, the “polymer flooding”using the hydrophobically associating copolymers according to theinvention can be combined with a preceding, so-called “surfactantflooding”. Here, before the polymer flooding, an aqueous surfactantformulation is initially injected into the mineral oil formation. As aresult of this, the interfacial tension between the water of formationand the actual mineral oil is reduced, thereby increasing the mobilityof the mineral oil in the formation. By combining the two techniques itis possible to increase the mineral oil yield.

Examples of suitable surfactants for the surfactant flooding comprisesurfactants having sulfate groups, sulfonate groups, polyoxyalkylenegroups, anionically modified polyoxyalkylene groups, betaine groups,glucoside groups or amine oxide groups, such as, for example,alkylbenzenesulfonates, olefinsulfonates or amidopropylbetaines.Preferably, anionic and/or betainic surfactants can be used.

The person skilled in the art is aware of the details for the technicalprocedure for the “polymer flooding” and of the “surfactant flooding”,and will use an appropriate technique depending on the type of deposit.

It is of course also possible to use surfactants and the copolymersaccording to the invention in a mixture.

For the just mentioned preferred use for the development, exploitationand completion of subterranean mineral oil deposits and natural gasdeposits, the copolymers described at the outset may be used. Thecopolymer described below can preferably be used. Accordingly, in onepreferred embodiment, the invention relates to a preferred,hydrophobically associating copolymer (A1).

Preferably, the copolymers (A1) comprises only monomers (a), (b) and (c)and particularly preferably only monomers (a) and (b). The monomers (a)are preferably only one or more monomers of the formula (I). Preferredmonomers (a) of the formula (I) have already been mentioned at thestart.

In the hydrophobically associating copolymer (A1), the monomers (a) areused in an amount of from 0.1 to 12% by weight, preferably 0.1 to 5% byweight, particularly preferably 0.2 to 3% by weight and veryparticularly preferably 0.3 to 2% by weight.

The amount of all of the monomers (b) together in the case of thecopolymer (A1) is 70 to 99.9% by weight, preferably 80 to 99.8% byweight, with regard to the amount of all of the monomers used. Theamount of all of the monomers (c) together is—if present—not more than29.9% by weight, preferably not more than 19.9% by weight.

The copolymers (A1) usually comprise at least one neutral hydrophilicmonomer (b1). Examples of suitable monomers (b1) comprise acrylamide andmethacrylamide, preferably acrylamide and derivatives thereof, such as,for example, N-methyl(meth)acrylamide, N,N′-dimethyl(meth)acrylamide andN-methylolacrylamide. Also to be mentioned are N-vinyl derivatives, suchas N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone orN-vinylcaprolactam. Also to be mentioned are monomers having OH groups,such as hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, allylalcohol, hydroxyvinyl ethyl ether, hydroxyvinyl propyl ether orhydroxyvinyl butyl ether. The monomer (b1) in copolymer (A1) ispreferably acrylamide or derivatives thereof, particularly preferablyacrylamide.

In a further embodiment of the invention, the monomer used in copolymer(A1) is at least one anionic monomer (b2) and/or at least one cationicmonomer (b2).

The anionic monomers (b2) are monomers comprising acid groups,preferably monomers which comprise at least one group selected from thegroup of —COOH, —SO₃H or −PO₃H₂. The monomers (b2) are preferablymonomers comprising carboxyl groups —COOH and/or sulfonic acid groups—SO₃H, particularly preferably monomers comprising sulfonic acid groups—SO₃H. They may of course also be the salts of the acidic monomers.Suitable counterions comprise in particular alkali metal ions such asLi⁺, Na⁺ or K⁺, and also ammonium ions such as NH₄ ⁺ or ammonium ionswith organic radicals.

Examples of anionic monomers (b2) comprise acrylic acid or methacrylicacid, crotonic acid, itaconic acid, maleic acid or fumaric acid,monomers comprising sulfonic acid groups, such as vinylsulfonic acid,allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS),2-methacrylamido-2-methylpropanesulfonic acid,2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonicacid or 2-acrylamido-2,4,4-trimethylpentanesulfonic acid or monomerscomprising phosphonic acid groups, such as vinylphosphonic acid,allylphosphonic acid, N-(meth)acrylamidoalkylphosphonic acids or(meth)acryloyloxyalkylphosphonic acids.

Examples of preferred anionic monomers (b2) comprise acrylic acid,vinylsulfonic acid, allylsulfonic acid,2-acrylamido-2-methylpropanesulfonic acid (AMPS),2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonicacid and 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, veryparticular preference being given to2-acrylamido-2-methylpropanesulfonic acid (AMPS).

Cationic monomers (b3) are generally monomers comprising ammoniumgroups, preferably the aforementioned monomers of the formulaeH₂C═C(R⁸)—CO—NR¹⁴—R¹²—NR¹³ ₃ ⁺X⁻ (Va) and/or H₂C═C(R⁷)—COO—R¹²—NR¹³ ₃⁺X⁻ (Vb), where the radicals and the ranges and/or species preferred ineach case are in each case as defined above. Examples of preferredmonomers (b3) comprise 3-trimethylammonium propylacrylamide chloride(DIMAPAQUAT).

Examples of such preferred copolymers (A1) comprise those which compriseat least one monomer (a) and acrylamide or one of the aforementionedacrylamide derivatives, in each case in the aforementioned amounts, andalso copolymers which, besides the monomers (a), comprise as monomer(b), monomers comprising sulfonic acid groups, in particular theaforementioned monomers comprising sulfonic acid groups and particularlypreferably AMPS.

In a further preferred embodiment of the invention, the copolymer (A1)comprises at least one neutral monomer (b1) and at least one anionicmonomer (b2) or at least one cationic monomer (b3), particularlypreferably at least one neutral monomer (b1) and at least one anionicmonomer (b2).

In this embodiment, it has proven useful to use the neutral monomer (b1)in an amount of from 20 to 95% by weight, preferably 30 to 90% byweight, and the anionic monomer (b2) and/or the cationic monomer (b3) inan amount of from 4.9 to 79.9% by weight, preferably 20 to 69.9% byweight, with the proviso that the total amount of the monomers (b)together is 70 to 99.9% by weight. The monomers (a) are used in theamounts given above.

Examples of such preferred copolymers (A1) comprise copolymers whichcomprise at least one monomer (a) and acrylamide or one of theaforementioned acrylamide derivatives and also, as monomer (b2),monomers comprising sulfonic acid groups, in particular theaforementioned monomers comprising sulfonic acid groups and particularlypreferably AMPS.

In a further preferred embodiment of the invention, the copolymer (A1)comprises at least one neutral monomer (b1), at least one anionicmonomer (b2) and at least one cationic monomer (b3).

In the case of this embodiment, it has proven useful to use the neutralmonomer (b1) in an amount of from 20 to 95% by weight, preferably 30 to90% by weight, and the ionic monomers (b2) and (b3) together in anamount of from 4.9 to 79.9% by weight, preferably 20 to 69.9% by weight,with the proviso that the total amount of the monomers (b) together is70 to 99.9% by weight. In one preferred embodiment, the molar ratio ofthe anionic monomers (b2) used and of the cationic monomers (b3)(b2)/(b3) is 0.5 to 1.5, preferably 0.7 to 1.3, particularly preferably0.8 to 1.2 and for example 0.9 to 1.1. This measure makes it possiblefor copolymers to be obtained which react particularly insensitively tosalt content.

Examples of such preferred copolymers (A1) comprise copolymers whichcomprise at least one monomer (a) and acrylamide or one of theaforementioned acrylamide derivatives and also, as monomer (b2) monomerscomprising sulfonic acid groups, in particular the aforementionedmonomers comprising sulfonic acid groups and particularly preferablyAMPS, and also, as monomer (b3), a salt of 3-trimethylammoniumpropylacrylamide.

The preparation of the copolymer (A1) preferably takes placephotochemically by means of the gel polymerization already described.

The copolymers (A1) preferably have a weight-average molecular weightM_(w) of from 1000000 g/mol to 20000000 g/mol, preferably 5000000 g/molto 20000000 g/mol and particularly preferably 10000000 g/mol to 20000000g/mol.

The copolymers (A1) are notable for the described use for thedevelopment, exploitation and completion, in particular the enhanced oilrecovery by particularly high thermal stability and salt stability.Furthermore, the inventive use of the monomers (a) of the formula (I)leads to copolymers with a particularly low gel fraction. Thiseffectively avoids blockage of the mineral oil deposits.

Second Preferred Use and Copolymers (A2) and (A3) Preferred for this

In a second preferred embodiment of the invention, the copolymersaccording to the invention can be used as additive for aqueousconstruction systems which comprise hydraulic binder systems. Examplesof such hydraulic binder systems comprise cement, lime, gypsum oranhydrite.

Examples of such construction systems comprise nonflowable constructionsystems such as tile adhesives, plasters or gap fillers, and flowableconstruction systems such as self-leveling floor screeds, sealing andrepair mortars, flow screeds, flow concrete, self-compacting concrete,underwater concrete or underwater mortar.

The preferred use amounts of the copolymers according to the inventionare between 0.001 and 5% by weight, based on the dry weight of theconstruction system, depending on the type of use.

The hydrophobically associating copolymers according to the inventioncan also be used in combination with nonionic polysaccharide derivativessuch as methylcellulose (MC), hydroxyethylcellulose (HEC),hydroxypropylcellulose (HPC), methylhydroxyethylcellulose (MHEC),methylhydroxypropylcellulose (MHPC) and also Welan gum or Diutan gum.

For dry mortar applications (e.g. tile adhesive, sealing mortar,plasters, flow screeds), the hydrophobically associating copolymersaccording to the invention are used in powder form. In this connection,it is advisable to select the size distribution of the particles byadapting the grinding parameters such that the average particle diameteris less than 100 μm and the fraction of particles with a particlediameter greater than 200 μm is less than 2% by weight. Preference isgiven to those powders whose average particle diameter is less than 60μm and the fraction of particles with a particle diameter greater than120 μm is less than 2% by weight. Particular preference is given tothose powders whose average particle diameter is less than 50 μm and thefraction of particles with a particle diameter greater than 100 μm isless than 2% by weight.

In the concrete, the copolymers according to the invention arepreferably used in the form of aqueous solutions. Of suitability forpreparing these solutions are particularly the relatively coarsegranules of the copolymers according to the invention with an averageparticle diameter between 300 μm and 800 μm, where the fraction ofparticles with a particle diameter of less than 100 μm is less than 2%by weight. The same is true if the copolymers according to the inventionare dissolved in other concrete additives or formulations of concreteadditives (e.g. in a flow agent).

For the just mentioned preferred use, as additive for hydraulicbinder-comprising aqueous construction systems, it is possible to use,besides the hydrophobically associating copolymers A1 according to theinvention, preferably the hydrophobically associating copolymer (A2)described below.

Accordingly, in a preferred embodiment, the invention relates to apreferred, hydrophobically associating copolymer (A2). The preferredcopolymer (A2) is suitable in particular as additive for nonflowableconstruction systems such as tile adhesives, plasters or gap fillers.

In the hydrophobically associating copolymer (A2), the monomers (a) areused in an amount of from 0.1 to 12% by weight, preferably 1 to 10% byweight and particularly preferably 1.5 to 8% by weight. Preferably, thecopolymer (A2) comprises only monomers (a), (b) and (d) and particularlypreferably only monomers (a) and (b).

The monomers (a) may be exclusively monomers (a) of the formula (I), inone preferred embodiment, however, in the case of copolymer (A2), themonomers (a) of the formula (I) can also be used in a mixture with otherhydrophobically associating monomers, preferably those of the generalformulae H₂C═C(R¹)—COO—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIa) and/orH₂C═C(R¹)—O—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIb). The meaning of the radicalsand indices and preferred ranges have already been described at thestart. In such a mixture, the fraction of the monomers of the formula(I) should usually be at least 25% by weight with regard to the amountof all of the monomers (a), preferably 40 to 90% by weight and forexample 40 to 60% by weight. Preferred monomers (a) of the formula (I)have already been mentioned above.

The copolymer (A2) comprises as monomers (b) at least one neutralmonomer (b1) and at least one anionic monomer (b2) and/or at least onecationic monomer (b3), preferably at least one neutral monomer (b1) andat least one cationic monomer (b3).

Examples of suitable monomers (b1), (b2) and (b3) have already beenspecified.

The neutral monomers (b1) in copolymer (A2) are preferably acrylamide ormethacrylamide and derivatives thereof, such as, for example,N-methyl(meth)acrylamide, N,N′-dimethyl(meth)acrylamide,N-methylolacrylamide and N-vinyl derivatives such as N-vinylformamide,N-vinylacetamide, N-vinylpyrrolidone or N-vinylcaprolactam. Preferredmonomers (b1) in the case of copolymer (A2) are acrylamide,methacrylamide and N-vinylpyrrolidone.

The anionic monomers (b2) in copolymer (A2) are monomers comprising acidgroups, preferably monomers which comprise at least one group selectedfrom the group of carboxyl groups —COOH, sulfonic acid groups —SO₃H orphosphonic acid groups —PO₃H₂.

The anionic monomers (b2) in the copolymer (A2) are preferably monomerscomprising sulfonic acid groups —SO₃H. Examples of preferred monomerscomprise vinylsulfonic acid, allylsulfonic acid,2-acrylamido-2-methylpropanesulfonic acid (AMPS),2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonicacid and 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, preferencebeing given to 2-acrylamido-2-methylpropanesulfonic acid (AMPS).

The cationic monomers (b3) in copolymer (A2) are preferably theaforementioned monomers of the formulae H₂C═C(R⁸)—CO—NR¹⁴—R¹²—NR¹³ ₃ ⁺X⁻(Va) and/or H₂C═C(R⁸)—COO—R¹²—NR¹³ ₃ ⁺X⁻ (Vb), where the radicals andthe ranges and/or species preferred in each case are in each case asdefined above. Particular preference is given to 3-trimethylammoniumpropylacrylamide chloride (DIMAPAQUAT).

In the copolymers (A2), the amount of the anionic monomers (b2) and ofthe cationic monomers (b3) is generally 25 to 80% by weight, with regardto the sum of all of the monomers, preferably 40 to 75% by weight,particularly preferably 45 to 70% by weight and that of the neutralmonomers (b1) is 15 to 60% by weight, preferably 20 to 50% by weight,with the proviso that the sum of the monomers (b1) and (b2) and (b3)together is 70 to 99.9% by weight. The monomers (a) are used in theamounts mentioned at the start.

Preferred copolymers (A2) comprise either an anionic monomer (b2) or acationic monomer (b3) in the amounts already given. If a mixture of (b2)and (b3) is used, the weight ratio (b2)/(b3) can in principle be chosenfreely.

For the just mentioned preferred use as additive for hydraulicbinder-comprising aqueous construction systems, the hydrophobicallyassociating copolymer (A3) described below can also be used.

Accordingly, in a third preferred embodiment, the invention relates to ahydrophobically associating copolymer (A3). The preferred copolymer (A3)is suitable in particular as additive for flowable construction systems,in particular for concrete, flow screeds, self-leveling trowelingcompositions and sealing mortars.

In the case of the hydrophobically associating copolymer (A3), themonomers (a) are used in an amount of from 0.1 to 12% by weight,preferably 1 to 10% by weight and particularly preferably 1.5 to 8% byweight. Preferably, the copolymer (A3) comprises only monomers (a), (b)and (d) and particularly preferably only monomers (a) and (b).

The monomers (a) may be exclusively monomers (a) of the formula (I), ina preferred embodiment in the case of copolymer (A3), however, themonomers (a) of the formula (I) can also be used in a mixture with otherhydrophobically associating monomers, preferably those of the generalformula H₂C═C(R¹)—COO—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIa) and/orH₂C═C(R¹)—O—(—CH₂—CH(R⁶)—O—)_(q)—R⁷ (IIb). The meaning of the radicalsand indices and also preferred ranges have already been described at thestart. In the case of such a mixture, the fraction of the monomers ofthe formula (I) should generally be at least 25% by weight with regardto the amount of all of the monomers (a), preferably 40 to 90% by weightand for example 40 to 60% by weight. Preferred monomers (a) of theformula (I) have already been mentioned above.

The copolymer (A3) comprises as monomers (b) at least one neutralmonomer (b1) and at least one anionic monomer (b2). Examples of suitablemonomers (b1) and (b2) have already been given.

The neutral monomers (b1) in copolymer (A3) are acrylamide ormethacrylamide and derivatives thereof, such as, for example,N-methyl(meth)acrylamide, N,N′-dimethyl(meth)acrylamide,N-methylolacrylamide and N-vinyl derivatives such as N-vinylformamide,N-vinylacetamide, N-vinylpyrrolidone or N-vinylcaprolactam. Preferredmonomers (b1) in copolymer (A3) are acrylamide, methacrylamide andN-vinylpyrrolidone.

The anionic monomers (b2) in copolymer (A3) are monomers comprising acidgroups, preferably monomers which comprise at least one group selectedfrom the group of carboxyl groups —COOH, sulfonic acid groups —SO₃H orphosphonic acid groups —PO₃H₂.

Preferably, in copolymer (A3) the monomers (b2) are monomers comprisingsulfonic acid groups —SO₃H. Examples of preferred monomers comprisevinylsulfonic acid, allylsulfonic acid,2-acrylamido-2-methylpropanesulfonic acid (AMPS),2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonicacid and 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, preferencebeing given to 2-acrylamido-2-methylpropanesulfonic acid (AMPS).

In the preferred copolymers (A3), the amount of anionic monomers (b2) isgenerally 25 to 94.9% by weight, with regard to the sum of all of themonomers, preferably 50 to 90% by weight, particularly preferably 60 to90% by weight and that of the neutral monomers (b1) is 5 to 50% byweight, preferably 5 to 30% by weight, with the proviso that the sum ofthe monomers (b1) and (b2) together is 70 to 99.9% by weight. Themonomers (a) are used in the amounts mentioned at the start.

For the use as additive for aqueous construction systems, it may beadvantageous to use additionally crosslinking monomers (d). These givethe hydrophobically associating copolymers (A1), (A2) and (A3) accordingto the invention a slightly branched or crosslinked structure.

Examples of preferred monomers (d) comprise triallylamine,triallylmethylammonium chloride; tetraallylammonium chloride,N,N′-methylenebisacrylamide, triethylene glycol bismethacrylate,triethylene glycol bisacrylate, polyethylene glycol(400)bismethacrylateand polyethylene glycol(400)bisacrylate.

The amount of monomers (d) is determined by the person skilled in theart depending on the desired properties of the copolymers. However, themonomers (d) must only be used in amounts such that the solubility inwater of the hydrophobically associating copolymers according to theinvention is not impaired. As a rule, the amount of the monomers (d)should not exceed 1% by weight with regard to the amount of all of themonomers used. Preferably, not more than 0.5% by weight and particularlypreferably not more than 0.1% by weight should be used; however, aperson skilled in the art can easily determine the maximum amount ofmonomers (d) that can be used.

Third Preferred Use and Copolymers (A4) Preferred for this

A fourth preferred embodiment of the invention deals with ahydrophobically associating copolymer (A4). The copolymer (A4) isusually an alkali-soluble dispersion. Copolymers of this type aresuitable in particular for use as thickeners in the field of detergentsand cleaners, cosmetic formulations and technochemical applications.

Besides the monomers (a), the copolymer (A4) comprises at least onemonomer (b) having acid groups, and at least one monomer (c). It is ofcourse also possible for several different monomers (c) to be used.

Preferred monomers (a) have already been mentioned at the start.

The monomers (b) having acid groups in copolymer (A4) are preferably themonomers (b2) already cited above. These are preferably monomers havingcarboxylic acid groups, such as, for example, acrylic acid, methacrylicacid, crotonic acid, itaconic acid, maleic acid or fumaric acid,particularly preferably (meth)acrylic acid.

The monomers (c) are preferably at least one (meth)acrylic acid ester ofthe general formula H₂C═C(R¹⁶)—COOR¹⁸, where R¹⁶ and R¹⁸ are as definedabove. Examples of such monomers (c) comprise esters of (meth)acrylicacid, for example alkyl(meth)acrylates, such as methyl(meth)acrylate,ethyl(meth)acrylate, n-propyl(meth)acrylate, n-butyl(meth)acrylate,2-ethylhexyl(meth)acrylate or 2-propylheptyl(meth)acrylate.

The copolymer (A4) preferably comprises at least one (meth)acrylic acidester in which R⁹ is an aliphatic, straight-chain or branchedhydrocarbon radical having 2 to 10 carbon atoms, preferably 4 to 8carbon atoms. Examples comprise ethyl(meth)acrylate,n-propyl(meth)acrylate, n-butyl(meth)acrylate,2-ethylhexyl(meth)acrylate or 2-propylheptyl(meth)acrylate.

In the hydrophobically associating copolymer (A4), the monomers (a) areused in an amount of from 0.1 to 20% by weight, preferably 0.5 to 15% byweight and particularly preferably 2 to 12% by weight, in each casebased on the total amount of all monomers in the copolymer.

The amount of monomers (b) in the copolymers (A4) is 25 to 94.9% byweight, preferably 25 to 50% by weight and particularly preferably 25 to40% by weight.

The amount of the monomers (c) in the copolymers (A4) is 5 to 74.9% byweight, preferably 25 to 74.5% by weight and particularly preferably 50to 70% by weight.

The copolymers (A4) according to the invention are particularly suitableas thickeners or rheology modifiers in coating slips, for example fordetergents, washing auxiliaries such as, for example, pre-spotters,fabric softeners, cosmetic formulations, pharmaceutical formulations,foods, coating slips, formulations for textile production, textileprinting pastes, printing inks, printing pastes for textile printing,paints, pigment slurries, aqueous formulations for generating foam,deicing mixtures, for example for aircraft, formulations for theconstruction industry, such as, for example, as additive for aqueousconstruction systems based on hydraulic binders such as cement, lime,gypsum and anhydrite, and also in water-based paint and coating systems.

Particular preference is given to the use in liquid detergents andcleaners. Besides a copolymer (A4), liquid detergents and cleanerscomprise one or more anionic, nonionic, cationic and/or amphotericsurfactants as well as other typical detergent additives. Preference isgiven to mixtures of anionic and nonionic surfactants. The totalsurfactant content of the liquid detergents or cleaners is preferably0.5 to 80% by weight and particularly preferably 0.5 to 50% by weight,based on the total liquid detergent or cleaner. Suitable surfactants areknown to the person skilled in the art and disclosed, for example, in WO2009/019225, page 8, line 34 to page 12, line 37.

The further components are one or more substances selected from thegroup of builders, bleaches, bleach activators, enzymes, electrolytes,nonaqueous solvents, pH extenders, fragrances, perfume carriers,fluorescent agents, dyes, hydrotopes, foam inhibitors, silicone oils,antiredeposition agents, optical brighteners, graying inhibitors,antishrink agents, crease protection agents, color transfer inhibitors,antimicrobial active ingredients, germicides, fungicides, antioxidants,corrosion inhibitors, antistats, ironing aids, phobicizing andimpregnation agents, antiswell and antislip agents and also UVabsorbers. Such detergent additives are known to the person skilled inthe art and disclosed, for example, in WO 2009/019225, page 12, line 39to page 24, line 4.

The following examples are intended to illustrate the invention in moredetail:

PART A) PREPARATION OF THE MONOMERS (I) Preparation of a HydroxybutylVinyl Ether Alkoxylate Having 22 EO Units and 8 PeO Units (Monomer M1)

52.3 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 2.99 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 436 g of EO were then metered in over the course of ca. 3.5h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 310 g of pentene oxide were metered inover the course of 3.0 h. The postreaction ran overnight.

The product had an OH number of 34.2 mg KOH/g (theory: 31.6 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 22 EO Unitsand 12 PeO Units (Monomer M2)

44.1 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 3.12 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 368 g of EO were then metered in over the course of ca. 3h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 392 g of pentene oxide were metered inover the course of 3.5 h. The postreaction ran overnight.

The product had an OH number of 31.9 mg KOH/g (theory: 26.5 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 22 ED Unitsand 16 PeO Units (Monomer M3)

37.8 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 3.01 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 315 g of EO were then metered in over the course of ca. 3h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 448 g of pentene oxide were metered inover the course of 4.5 h. The postreaction ran overnight.

The product had an OH number of 25.2 mg KOH/g (theory: 22.7 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 22 EO Unitsand 20 PeO Units (Monomer M4)

33.2 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 3.01 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 277 g of EO were then metered in over the course of ca. 2.5h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 492 g of pentene oxide were metered inover the course of 5 h. The postreaction ran overnight.

The product had an OH number of 23.2 mg KOH/g (theory: 20.0 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 68 EO Unitsand 8 PeO Units (Monomer M5)

24.3 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 2.98 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 627 g of EO were then metered in over the course of ca. 5.5h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 144 g of pentene oxide were metered inover the course of 2.5 h. The postreaction ran overnight.

The product had an OH number of 17.6 mg KOH/g (theory: 14.7 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 22 EO Unitsand 12 PeO Units (Monomer M6)

22.5 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 3.01 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 580 g of EO were then metered in over the course of ca. 5h. After a postreaction for half an hour at 140° C., the reactor wascooled to 125° C. and a total of 200 g of pentene oxide were metered inover the course of 3.0 h. The postreaction ran overnight.

The product had an OH number of 16.8 mg KOH/g (theory: 13.5 mg KOH/g).The OH number was determined by means of the ESA method.

Preparation of a Hydroxybutyl Vinyl Ether Alkoxylate with 132 EO Unitsand 8 PeO Units (Monomer M7)

14.1 g of hydroxybutyl vinyl ether were initially introduced into a 1 lstirred autoclave made of stainless steel. 3.02 g of KOMe (32% strengthin MeOH) were then metered in and the methanol was drawn off at 80° C.and ca. 30 mbar. The mixture was then heated to 140° C., the reactor wasflushed with nitrogen and a nitrogen pressure of 1.0 bar wasestablished. 706 g of EO were then metered in over the course of ca. 8h. After a postreaction for half an hour at 140° C., the reactor wascooled. On the next day, at 125° C., a total of 83.6 g of pentene oxidewere metered in over the course of 2.0 h. A postreaction of 5 hours at125° C. followed.

The product had an OH number of 10.2 mg KOH/g (theory: 8.5 mg KOH/g).The OH number was determined by means of the ESA method.

The data for the synthesized monomers M1 to M7 are summarized in table 1below. All monomers have a terminal OH group.

TABLE 1 Synthesized monomers (I) Block 1 Block 2 Monomer Number ofNumber of OH number No. Alcohol EO units Alkylene oxide units [mg KOH/g]M1 4-hydroxybutyl vinyl ether 22 pentene oxide 8 34.2 M2 4-hydroxybutylvinyl ether 22 pentene oxide 12 31.9 M3 4-hydroxybutyl vinyl ether 22pentene oxide 16 25.2 M4 4-hydroxybutyl vinyl ether 22 pentene oxide 2023.2 M5 4-hydroxybutyl vinyl ether 68 pentene oxide 8 17.6 M64-hydroxybutyl vinyl ether 68 pentene oxide 12 16.8 M7 4-hydroxybutylvinyl ether 132 pentene oxide 8 10.2

For the comparative experiments, commercially available, hydrophobicallyassociating monomers of the following general formula were used:H₂C═C(CH₃)—COO-(EO)_(x)—R. R and x here in the monomers M8 and M9 havethe following meaning:

M8: x=25, R=tristyrylphenyl

M9: x=7, R=n-dodecyl

PART B) PREPARATION OF THE HYDROPHOBICALLY ASSOCIATING COPOLYMERS PartB-1) Preparation of Hydrophobically Associating Copolymers of the Type(A1) Example 1

Hydrophobically associating amphoteric copolymer of the type (A1) ofacrylamide (35.9% by weight), an anionic monomer(acrylamido-2-methylpropanesulfonic acid, Na salt, 32.1% by weight), acationic monomer (3-trimethylammonium propylacrylamide chloride, 31.0%by weight) and the monomer M1 according to the invention (1% by weight)

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

139.1 g  acrylamido-2-methylpropanesulfonic acid, Na salt (58% strengthby weight solution in water; 17.6 mol %), 1.2 g silicone defoamer, 2.4 gpentasodium diethylenetriaminepentaacetate (complexing agent), 111.6 g 3-trimethylammonium propylacrylamide chloride (60% strength by weightsolution in water; 18.8 mol %), 160.1 g  acrylamide (50% strength byweight solution in water; 63.5 mol %), 2.1 g monomer M1,  12 g urea

1.5 g of sodium hypophosphite (0.1% strength by weight solution inwater) were added as molecular weight regulator. The solution wasadjusted to pH 6 using 20% strength sodium hydroxide solution, renderedinert by flushing for 10 minutes with nitrogen and cooled to ca. 5° C.The solution was transferred to a plastic container and then, insuccession, 150 ppm of 2,2′-azobis(2-amidinopropane)dihydrochloride (as1% strength by weight solution), 10 ppm of tert-butyl hydroperoxide (as0.1% strength by weight solution) and 20 ppm of sodiumhydroxymethanesulfinate (as 1% strength by weight solution) were added.The polymerization was started by irradiating with UV light (two Philipstubes; Cleo Performance 40 W). After ca. 2 h, the hard gel was removedfrom the plastic container and cut using scissors into gel cubesmeasuring ca. 5 cm×5 cm×5 cm. Before the gel cubes were comminuted usinga conventional meat grinder, they were coated with a standard commercialrelease agent. The release agent is a polydimethylsiloxane emulsionwhich was diluted 1:20 with water. The resulting gel granules were slumpuniformly on drying meshes and dried to constant weight in a convectiondrying oven at ca. 90 to 120° C. in vacuo.

Comparative Example 1

Polymer analogous to example 1, but without hydrophobically associatingmonomer

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

139.1 g  acrylamido-2-methylpropanesulfonic acid, Na salt (58% strengthby weight solution in water; 17.4 mol %), 1.2 g silicone defoamer, 2.4 gpentasodium diethylenetriaminepentaacetate (complexing agent), 111.6 g 3-trimethylammonium propylacrylamide chloride (60% strength by weightsolution in water; 18.5 mol %), 164.5 g  acrylamide (50% strength byweight solution in water; 64.2 mol %),  12 g urea

The solution was adjusted to pH 6 using 20% strength sodium hydroxidesolution, rendered inert by flushing for 10 minutes with nitrogen andcooled to ca. 5° C. The solution was transferred to a plastic containerand then, in succession, 150 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 10 ppm of tem-butyl hydroperoxide (as 0.1% strength by weightsolution) and 20 ppm of sodium hydroxymethanesulfinate (as 1% strengthby weight solution) were added. The polymerization was started byirradiating with UV light (two Philips tubes; Cleo Performance 40 W).After ca. 2 h, the hard gel was removed from the plastic container andcut using scissors into gel cubes measuring ca. 5 cm×5 cm×5 cm. Beforethe gel cubes were comminuted using a conventional meat grinder, theywere coated with a standard commercial release agent. The release agentis a polydimethylsiloxane emulsion which was diluted 1:20 with water.The resulting gel granules were distributed uniformly on drying meshesand dried to constant weight in a convection drying oven at ca. 90 to120° C. in vacuo.

Comparative Example 2

Polymer analogous to example 1, but instead of the hydrophobicallyassociating monomer according to the invention, monomer M8 was used

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

139.1 g acrylamido-2-methylpropanesulfonic acid, Na salt (58% strengthby weight solution in water; 17.6 mol %),  1.2 g silicone defoamer,  2.4g pentasodium diethylenetriaminepentaacetate (complexing agent), 111.6 g3-trimethylammonium propylacrylamide chloride (60% strength by weightsolution in water; 18.8 mol %), 155.2 g acrylamide (50% strength byweight solution in water; 63.5 mol %),  3.5 g monomer M8,   12 g urea

1.5 g of sodium hypophosphite (0.1% strength by weight solution inwater) were added as molecular weight regulator. The solution wastransferred to a plastic container and then, in succession, 150 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 10 ppm of ten′ butyl hydroperoxide (as 0.1% strength byweight solution) and 20 ppm of sodium hydroxymethanesulfinate (as 1%strength by weight solution) were added. The polymerization was startedby irradiating with UV light (two Philips tubes; Cleo Performance 40 W).After ca. 2 h, the hard gel was removed from the plastic container andcut using scissors into gel cubes measuring ca. 5 cm×5 cm×5 cm. Beforethe gel cubes were comminuted using a conventional meat grinder, theywere coated with a standard commercial release agent. The release agentis a polydimethylsiloxane emulsion which was diluted 1:20 with water.The resulting gel granules were distributed uniformly on drying meshesand dried to constant weight in a convection drying oven at ca. 90 to120° C. in vacuo.

Comparative Example 3

Polymer analogous to example 1, but instead of the hydrophobicallyassociating monomer according to the invention, the monomer M9 was used

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

139.0 g acrylamido-2-methylpropanesulfonic acid, Na salt (58% strengthby weight solution in water; 17.6 mol %),  1.2 g silicone defoamer,  2.4g pentasodium diethylenetriaminepentaacetate (complexing agent), 111.6 g3-trimethylammonium propylacrylamide chloride (60% strength by weightsolution in water; 18.8 mol %), 155.2 g acrylamide (50% strength byweight solution in water; 63.4 mol %),  2.2 g monomer M9,   12 g urea

1.5 g of sodium hypophosphite (0.1% strength by weight solution inwater) were added as molecular weight regulator. The solution wastransferred to a plastic container and then, in succession, 150 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 10 ppm of tert-butyl hydroperoxide (as 0.1% strength byweight solution) and 20 ppm of sodium hydroxymethanesulfinate (as 1%strength by weight solution) were added. The polymerization was startedby irradiating with UV light (two Philips tubes; Cleo Performance 40 W).After ca. 2 h, the hard gel was removed from the plastic container andcut using scissors into gel cubes measuring ca. 5 cm×5 cm×5 cm. Beforethe gel cubes were comminuted using a conventional meat grinder, theywere coated with a standard commercial release agent. The release agentis a polydimethylsiloxane emulsion which was diluted 1:20 with water.The resulting gel granules were distributed uniformly on drying meshesand dried to constant weight in a convection drying oven at ca. 90 to120° C. in vacuo.

Examples 2 to 8

Hydrophobically associating copolymers of the type (A1) of acrylamide(48% by weight) and acrylamido-2-methylpropanesulfonic acid, Na salt(50% by weight) and a hydrophobically associating monomer according tothe invention (2% by weight)

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

290 g  distilled water, 242.5 g  acrylamido-2-methylpropanesulfonicacid, Na salt (58% strength by weight solution in water; 24.7 mol %),1.2 g silicone defoamer, 2.4 g pentasodiumdiethylenetriaminepentaacetate (complexing agent), 228.8 g  acrylamide(50% strength by weight solution in water; 75.2 mol %), 4.6 g monomersof one of the monomers M1 to M7 (as in table)

The solution was adjusted to pH 6 using 20% strength sodium hydroxidesolution, rendered inert by flushing for 10 minutes with nitrogen andcooled to ca. 5° C. The solution was transferred to a plastic containerand then, in succession, 200 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 10 ppm of tert-butyl hydroperoxide (as 0.1% strength byweight solution), 5 ppm of FeSO₄*7H₂O (as 1% strength by weightsolution) and 6 ppm of sodium bisulfite (as 1% strength by weightsolution) were added. The polymerization was started by irradiating withUV light (two Philips tubes; Cleo Performance 40 W). After ca. 2 h, thehard gel was removed from the plastic container and cut using scissorsinto gel cubes measuring ca. 5 cm×5 cm×5 cm. Before the gel cubes werecomminuted using a conventional meat grinder, they were coated with astandard commercial release agent. The release agent is apolydimethylsiloxane emulsion which was diluted 1:20 with water. Theresulting gel granules were distributed uniformly on drying meshes anddried to constant weight in a convection drying oven at ca. 90 to 120°C. in vacuo.

Part B-2) Preparation of Hydrophobically Associating Copolymers of theTypes (A2) and (A3) Example 9

Hydrophobically associating copolymer of the type (A2) of acrylamide(33% by weight), 3-(acrylamino)propyltrimethylammonium chloride (57% byweight), acrylic acid (2% by weight) and a mixture of thehydrophobically associating monomer M8 (3% by weight) and the monomer M5according to the invention (5% by weight)

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

170 g  distilled water, 1.6 g silicone defoamer, 2.4 g pentasodiumdiethylenetriaminepentaacetate (complexing agent), 5.8 g acrylic acid(99.5% strength by weight; 3.6 mol %), 273.6 g 3-(acrylamino)propyltrimethylammonium chloride (60% strength by weightsolution in water; 35.7 mol %), 190.5 g  acrylamide (50% strength byweight solution in water; 60.3 mol %), 14.4 g  monomer M8 (60% strengthby weight solution in water), 14.4 g  monomer M5 (0.2 mol %),

0.5 g of formic acid (10% strength by weight solution in water) wasadded as molecular weight regulator. The solution was adjusted to pH 7using 20% strength sodium hydroxide solution, rendered inert by flushingfor 5 minutes with nitrogen and cooled to ca. 5′C. The solution wastransferred to a plastic container and then, in succession, 250 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 20 ppm of tert-butyl hydroperoxide (as 0.1% strength byweight solution) and 30 ppm of sodium bisulfite (as 1% strength byweight solution) were added. The polymerization was started byirradiating with UV light (two Philips tubes; Cleo Performance 40 W).After ca. 2 h, the hard gel was removed from the plastic container andcut using scissors into gel cubes measuring ca. 5 cm×5 cm×5 cm. Beforethe gel cubes were comminuted using a standard commercial meat grinder,they were coated with a standard commercial release agent. The releaseagent is a polydimethylsiloxane emulsion which was diluted 1:20 withwater. The resulting gel granules were distributed uniformly on dryingmeshes and dried to constant weight in a convection drying oven at ca.90 to 120° C. in vacuo.

Example 10

Hydrophobically associating copolymer of the type (A2) ofdimethylacrylamide (32% by weight),3-(acrylamino)propyltrimethylammonium chloride (59% by weight), acrylicacid (2% by weight) and a mixture of the hydrophobically associatingmonomer M8 (2% by weight) and a monomer M5 according to the invention(5% by weight)

The procedure was as in example 9, except that the following componentswere used:

  170 g distilled water,  1.6 g silicone defoamer,  6.9 g acrylic acid(99.5% strength by weight; 4.3 mol %), 338.2 g3-(acrylamino)propyltrimethylammonium chloride (60% strength by weightsolution in water; 44.6 mol %), 111.2 g dimethylacrylamide (50.6 mol %), 14.4 g monomer M8 (60% strength by weight solution in water),  17.2 gmonomer M5

Example 11

Hydrophobically associating copolymer of type (A2) of acrylamide (10% byweight), N-vinylpyrrolidone (28% by weight),acrylamido-2-methylpropanesulfonic acid, Na salt (50% by weight),acrylic acid (2% by weight) and the monomer M6 according to theinvention (10% by weight)

The procedure was as in example 9, except that the following componentswere used:

 170 g distilled water,  1.6 g silicone defoamer,  2.4 g pentasodiumdiethylenetriaminepentaacetate,  6.1 g acrylic acid (99.5% strength byweight; 4.2 mol %), 336.1 g  acrylamido-2-methylpropanesulfonic acid, Nasalt (58% strength by weight solution in water; 36.2 mol %), 60.9 gacrylamide (50% strength by weight solution in water; 21.2 mol %), 85.9g N-vinylpyrrolidone (38.1 mol %) 30.4 g monomer M6

Example 12

Hydrophobically associating copolymer of the type (A2) of acrylamide(10% by weight), N-vinylpyrrolidone (38.1% by weight),3-(acrylamino)propyltrimethylammonium chloride (50% by weight), acrylicacid (2% by weight) and the monomer M6 according to the invention (10%by weight)

The procedure was as in example 9, except that the following componentswere used:

 170 g distilled water,  1.6 g silicone defoamer,  2.4 g pentasodiumdiethylenetriaminepentaacetate,  7.7 g acrylic acid (99.5% strength byweight; 4.1 mol %), 320.0 g  3-(acrylamino)propyltrimethylammoniumchloride (60% strength by weight solution in water; 36.2 mol %), 79.4 gacrylamide (50% strength by weight solution in water; 21.2 mol %),108.6  N-vinylpyrrolidone (38.1 mol %), 38.4 g monomer M6

Example 13

Hydrophobically associating copolymer of the type (A3) ofdimethylacrylamide (19.2% by weight), acrylamido-2-methylpropanesulfonicacid, Na salt (77% by weight) and a mixture of the hydrophobicallyassociating monomer M8 (0.8% by weight) and a monomer M1 according tothe invention (3% by weight)

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

1377 g   distilled water,   3 g silicone defoamer, 315 g acrylamido-2-methylpropanesulfonic acid, Na salt (58% strength by weightsolution in water; 65.5 mol %), 35.8 g  dimethylacrylamide (34.1 mol %),2.6 g monomer M8 (60% strength by weight solution in water), 5.6 gmonomer M1

The solution was adjusted to pH 7 using 20% strength sodium hydroxidesolution, rendered inert by flushing for 10 min with nitrogen, heated toca. 50° C. and, in succession, 1500 ppm of sodium peroxodisulfate (as20% strength by weight solution) and 240 ppm of tetraethylenepentamine(as 20% strength by weight solution) were added. After ca. 2 hours, thepolymer solution was dried to constant weight in a convection dryingoven at ca. 90 to 120° C. in vacuo and finally ground.

Example 14

Hydrophobically associating copolymer of the type (A3) ofdimethylacrylamide (35% by weight), acrylamido-2-methylpropanesulfonicacid, Na salt (60% by weight) and the monomer M1 according to theinvention (5% by weight)

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

 539.2 g acrylamido-2-methylpropanesulfonic acid, Na salt (58% strengthby weight solution in water; 44.9 mol %),   1.6 g silicone defoamer,143.51 g dimethylacrylamide (54.7 mol %),  20.4 g monomer M1

4 g of formic acid (10% strength by weight solution in water) were addedas molecular weight regulator. The solution was adjusted to pH 7 using20% strength sodium hydroxide solution, rendered inert by flushing for10 min with nitrogen and cooled to ca. 5° C. The solution wastransferred to a plastic container and then, in succession, 150 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 6 ppm of tert-butyl hydroperoxide (as 0.1% strength by weightsolution), 6 ppm of sodium hydroxymethanesulfinate (as 1% strength byweight solution) and 3 ppm of FeSO₄*7H₂O (as 1% strength by weightsolution) were added. The work-up was carried out as described above.

Comparative Example 4

Hydrophobically associating copolymer with acrylamide and3-(acrylamino)propyltrimethylammonium chloride without monomersaccording to the invention

The procedure was as in example 9, except that the following componentswere used:

170 g  distilled water, 1.6 g silicone defoamer, 2.4 g pentasodiumdiethylenetriaminepentaacetate, 5.4 g acrylic acid (99.5% strength byweight; 2.9 mol %), 148 g  3-(acrylamino)propyltrimethylammoniumchloride (60% strength by weight solution in water; 18.3 mol %), 259.7g  acrylamide (50% strength by weight solution in water; 78.6 mol %),20.0 g  polyethylene glycol (3000) vinyl oxybutyl ether (VOB, 60%strength by weight solution in water; 0.2 mol %), 8.0 g monomer M8 (60%strength by weight solution in water).

Comparative Example 5

Hydrophobically associating copolymer with dimethylacrylamide andacrylamido-2-methylpropanesulfonic acid, Na salt without monomeraccording to the invention

The procedure was as in example 9, except that the following componentswere used:

170 g distilled water,  1.6 g silicone defoamer,  2.4 g pentasodiumdiethylenetriaminepentaacetate, 528 g acrylamido-2-methylpropanesulfonicacid, Na salt (58% strength by weight solution in water; 48.1 mol %),175 g acrylamide (50% strength by weight solution in water; 51.5 mol %),29.2 g  polyethylene glycol (3000) vinyl oxybutyl ether (VOB, 60%strength by weight solution in water; 0.2 mol %), 11.9 g  monomer M8(60% strength by weight solution in water)

Comparative Example 6

The following components were mixed together in a 2 l three-necked flaskfitted with stirrer and thermometer:

 1.6 g silicone defoamer, 578.0 g acrylamido-2-methylpropanesulfonicacid, Na salt (58% strength by weight solution in water; 62.2 mol %),104.8 g acrylamide (50% strength by weight solution in water; 36.4 mol%),  43.5 g polyethylene glycol (1100) vinyloxy butyl ether (VOB, 60%strength by weight solution in water)

300 ppm of formic acid (10% strength by weight solution in water) wereadded as molecular weight regulator. The solution was adjusted to pH 7using 20% strength sodium hydroxide solution, rendered inert by flushingfor 10 min with nitrogen and cooled to ca. 5° C. The solution wastransferred to a plastic container and then, in succession, 150 ppm of2,2′-azobis(2-amidinopropane)dihydrochloride (as 1% strength by weightsolution), 6 ppm of tert-butyl hydroperoxide (as 0.1% strength by weightsolution), 6 ppm of sodium hydroxymethanesulfinate (as 1% strength byweight solution) and 3 ppm of FeSO₄*7H₂O (as 1% strength by weightsolution) were added. The work-up was carried out as described above.

Part B-3) Preparation of Hydrophobically Associating CopolymerDispersions of the Type (A4) Comparative Example 7

The copolymer preparation was carried out in accordance with the methoddescribed below. The resulting aqueous polymer dispersion comprised thecopolymers in their acid form.

In a stirred apparatus, consisting of a 4 liter HWS vessel with anchorstirrer (150 rpm), reflux condenser, internal thermosensor and meteringstation, 484.5 g of demineralized water (DM water) and 8.21 g of anemulsifier (sodium lauryl ether sulfate; 28% strength in water) weremixed as initial charge.

At 75° C., 12.49 g of a 7% strength aqueous sodium peroxodisulfatesolution were added to this solution and the mixture was stirred at 75°C. for 5 minutes. Then, at 75° C. and with further stirring, an emulsionconsisting of 429.91 g of completely demineralized water, the monomers(140.82 g of methacrylic acid, 161 g of ethyl acrylate, and 161 g ofn-butyl acrylate) and 16.43 g of sodium lauryl ether sulfate (27-28%strength in water) were uniformly metered in over the course of 2 hours.The reaction mixture was then stirred for a further 1 hour at 75° C. andthen brought to room temperature. At room temperature, 0.23 g of a 4%strength solution of [EDTA-Fe]K (CAS No. 54959-35-2) and 9.2 g of a 5%strength hydrogen peroxide solution were added, and 69 g of a 1%strength ascorbic acid solution was metered in uniformly over the courseof 30 min. This gave an aqueous polymer dispersion with 31% solidscontent.

To characterize the dispersion, the following values were measured:

Solids Content:

The dispersion was dried at 140° C. for 30 min and the solids contentwas determined in percent from the ratio of dry residue to initialweight.

Particle Size:

The dispersion was diluted to 0.01% and the particle size was measuredby means of light scattering in the High Performance Particle Sizer 5001(HPPS) from Malvern Instruments.

LD Value:

The dispersion was diluted to 0.01% and the light transmission (LT) ofthe dispersion compared to pure water was measured visually in the HachDR/2010 as a measure of the particle size.

The results are summarized in table 2.

Example 15

In a stirred apparatus consisting of a 4 liter HWS vessel with anchorstirrer (150 rpm), reflux condenser, internal thermosensor and meteringstation, 484.5 g of demineralized water (DM water) and 4.11 g of anemulsifier 28% strength (sodium lauryl ether sulfate; 28% strength inwater) in water were mixed as initial charge.

At 75° C., 12.49 g of a 7% strength aqueous sodium peroxodisulfatesolution were added to this solution and the mixture was stirred at 75°C. for 5 minutes. Then, at 75° C. and with further stirring, theemulsion consisting of 429.91 g of completely demineralized water (DMwater), the monomers 140.82 g of methacrylic acid, 149.94 g of ethylacrylate, 159.56 g of n-butyl acrylate and 12.5 g of the associativemonomer M1 according to the invention and 20.54 g of sodium lauryl ethersulfate (28% strength in water) were metered in uniformly over thecourse of 2 hours. The reaction mixture was then stirred for a further 1hour at 75° C. and then brought to room temperature. At roomtemperature, 0.23 g of a 4% strength solution of [EDTA-Fe]K (CAS No.54959-35-2) and 9.2 g of a 5% strength hydrogen peroxide solution wereadded, and 69 g of a 1% strength ascorbic acid solution were metered inuniformly over the course of 30 min. This gave an aqueous polymerdispersion with 31% solids content.

The dispersion was characterized as described above. The results aresummarized in table 2.

Examples 16 to 21

Further dispersions were prepared analogously to the procedure ofexample 15, except in each case the hydrophobically associating monomerM1 was replaced by another monomer M2 to M7. The dispersions were ineach case characterized as described above. The results are summarizedin each case in table 2.

TABLE 2 Data of the resulting dispersions Hydro- Number Co- phobicallyNumber of pentene Solids Particle LT—0.1% polymer associating of EOoxide content size strength No. monomer units units (%) (nm) (%) C 7without 15 M1 22 8 31.1 76 97 16 M7 132 8 31.0 65 98 17 M5 68 8 30.8 6398 18 M6 68 12 30.3 63 98 19 M2 22 12 31.0 64 98 20 M3 22 16 30.8 66 9821 M4 22 20 30.8 63 98

PART C) APPLICATIONS-RELATED TESTS Part C-1) Test of the Copolymers ofthe Type A1

Determination of the Gel Fraction:

1 g of the respective copolymer is stirred in 249 g of syntheticseawater in accordance with DIN 50900 for 24 h until completelydissolved. The solution is then filtered over a 200 μm sieve and thevolume of the residue remaining on the sieve is measured. This value isthe gel fraction.

Determination of the Viscosity:

The viscosity of the filtrate is measured using a rheometer withdouble-slit geometry at 7 s⁻¹ and 60° C.

The results are summarized in tables 3 and 4.

TABLE 3 Results of the applications-related experiments with amphotericcopolymers of the type (A1) Hydrophobically associating Copolymermonomer Gel fraction [ml] Viscosity [mPas] Example 1 M1 <5 25 C1 without<5 10 C2 M8 8 16 C3 M9 9 12

TABLE 4 Results of the applications-related experiments with copolymersof the type (A1) of acrylamide and AMPS Number of Monomer Number of EOpentene oxide Viscosity Copolymer used units units [mPas] Example 2 M122 8 27 Example 3 M2 22 12 52 Example 4 M3 22 16 9 Example 5 M4 22 20 22Example 6 M5 68 8 17 Example 7 M6 68 12 30 Example 8 M7 132 8 3

The data in table 3 show that the solution of the copolymer according tothe invention according to example 1 in seawater has the highestviscosity of all of the tested copolymers for a simultaneously low gelfraction. The copolymer according to comparative example 1, thus withoutmonomers which can hydrophobically associate, likewise has a low gelfraction, but the viscosity is also naturally lower. The monomersaccording to prior art M8 and M9 do increase the viscosity, as expected,but not as great by far as the monomers used according to the inventionand, moreover, the gel fraction is in each case significantly higher.

Table 4 shows that the viscosity of the copolymers according to theinvention depends on the nature of the monomers used. Example 3represents the best currently known embodiment of the invention.

Part C-2) Test of the Copolymers of the Type (A2) and (A3)

Test in a Tile Adhesive Mortar:

The properties of the copolymers of the type (A2) were tested in a testmixture of a tile adhesive mortar. The composition of the test mixtureis given in DE 10 2006 050 761 A1, page 11, table 1. This is aready-to-use formulated dry mixture to which in each case 0.5% by weightof the hydrophobically associating copolymer to be tested was admixed insolid form. After the dry mixing, a certain amount of water was addedand the mixture was intensively stirred using a suitable mixing device(drilling machine with G3 mixer). The required mixing time was measured.The tile adhesive was initially left to ripen for 5 min.

The following tests were carried out on the stirred tile adhesivemortar:

Slump The determination of the slump was carried out in accordance withDIN 18555, part 2 and was carried out directly after the ripening timeand, if appropriate, at later time points. Water retention The waterretention was ascertained 15 min after stirring in accordance with DIN18555, part 7. Wetting The tile adhesive formulation was applied to aconcrete slab in accordance with EN 1323 and after 10 min, a tile (5 cm× 5 cm) was laid onto it. The tile was then weighted with a weight of 2kg for 30 s. After a further 60 min, the tile was removed and it wasascertained to what percentage the back of the tile was still adhered toby tile mortar. Slip The slip was determined 3 min after stirring inaccordance with DIN EN 1308. The slip distance in mm is stated. Tack Thedetermination of the tack and/or ease of handling of the test mixturewas carried out by a qualified person skilled in the art. Air porestability The determination of the air pore stability was carried outvisually by a qualified person skilled in the art.

The copolymers used in each case and the results obtained are summarizedin table 5.

Test in a Self-Compacting Concrete

The properties of the copolymers of the type (A3) were tested in a testmixture of a self-compacting concrete. The composition of the testmixture is given in DE 10 2004 032 304 A1, page 23, table 11. Thepolymers to be tested are used in each case in an amount of 0.02% byweight.

The preparation of the mortar mixtures was carried out in accordancewith section [0105] of DE 10 2004 032 304 A1, the determination of theflowability (slump flow) was carried out in accordance with the methoddescribed in section [0106], and the bleeding and the sedimentation wereassessed visually by a person skilled in the art. The values were takendirectly after stirring and after 20 minutes.

The copolymers used in each case and the results obtained are summarizedin table 6.

TABLE 5 Results of the examples and comparative examples Copolymer C6Cellulose Example Example Example Example Example ether MHPC 6 9 10 1112 C4 C5 30 000 Mixing time [s] 16 18 20 15 12 16 18 6 Slump 19.0 18.418.3 20.5 18.1 17.2 18.2 16.2 Water retention [%] 98.0 98.1 98.0 97.798.0 97.8 98.1 98.6 Wetting [%] 88.2 95 87 90 93 89 91 70 Slip [mm] 3 21 5 2 2 3 8 Tack good high high good high high high very high Air porestability good very good very good good very good good very good good

TABLE 6 Results of the examples and comparative examples C8 Polymeraccording to C7 DE102004032304 Exam- Exam- Exam- Without A1 Copolymerple 8 ple 13 ple 14 polymer Example 8 Slump 72.5 73 72 75 74 (immediate)[cm] Bleeding no no no severe no (immediate) Sedimentation no no nosevere no (immediate) Slump 72 73 72 74 72 (after 20 min) [cm] Bleedingno no no severe no (after 20 min) Sedimentation no no no severe no(after 20 min)

Part C-3) Test of the Copolymers of the Type A4

Preparation of an Exemplary Liquid Detergent

The following stock formulations are prepared (% by weight, based on thefinished formulation):

Component Amount Anionic surfactant (linear alkylbenzene sulfonic acid,C₁₀₋₁₃) 13.44 Nonionic surfactant (C_(13/15) oxo alcohol, alkoxylatedwith ca. 7 7.5 EO units) Coconut oil fatty acid 8.5 KOH 4.38 Sodiumcitrate dihydrate 3 1,2-Propylene glycol 8 Ethanol 2 Water qs

The above constituents were mixed and topped up to 90% by weight withwater, i.e. a formulation gap of 10% by weight remained. The stockformulations were adjusted to pH 8.6 with KOH.

For the (unthickened) reference formulations, the stock formulationswere topped up to 100% by weight with water. For the thickened testformulations, the stock formulations were topped up with thickenerdispersion and water so that, taking into consideration the solidscontent of the dispersion, a thickener concentration of 1.4% by weight,based on the finished formulation, was established. Prior to theviscosity measurement, the formulations were left to stand for at least5 hours.

The low-shear viscosity was measured taking into consideration theinstructions in accordance with DIN 51550, DIN 53018, DIN 53019 usingthe Brookfield viscometer model RV-03 at a rotary speed of 20revolutions per minute using spindle No. 62 at 20° C. The viscosity ofthe unthickened reference formulations was 112 mPas.

To quantify the transparency of the thickened formulations, thetransmission in % was measured at 440 nm at 23° C. using a LICO 200 fromDr. Lange. The values found for the thickened formulations are given asa percentage, relative to the transmission of the unthickened referenceformulation.

The results are summarized in tables 7.

TABLE 7 Applications-related evaluation of the thickener dispersions:Formulation with 1.4% by weight thickener Low-shear viscosity Polymerused according to Transmission (%) (mPas) Without thickening polymer —112 Comparative example 7 99 1023 (without monomer (a)) Example 15 991392 Example 16 100 1472 Example 17 100 1392 Example 18 100 1424 Example19 100 1360 Example 20 100 1472 Example 21 100 1408

It can be seen that the use of the thickeners leads to a considerableviscosity increase compared to the reference formulation withoutthickener.

Examples 15 to 21 which comprise the hydrophobically associatingmonomers according to the invention produce a significantly higherviscosity than comparison sample 7 which does not comprise anyhydrophobically associating monomer. The use of the associative monomersaccording to the invention does not adversely effect the hightransparency of the liquid detergent formulation, expressed by thetransmission measurement.

The invention claimed is:
 1. An additive for aqueous construction systems which comprise a water-soluble, hydrophobically associating copolymer comprising at least (a) 0.1 to 20% by weight of at least one monoethylenically unsaturated, hydrophobically associating monomer (a), and (b) 25% by weight to 99.9% by weight of at least one monoethylenically unsaturated hydrophilic monomer (b) different therefrom, where the quantitative data are based in each case on the total amount of all of the monomers in the copolymer, wherein at least one of the monomers (a) is a monomer of the general formula (I) H₂C═C(R¹)—R⁴—O—(—CH₂—CH(R²)—O—)_(k)—(—CH₂—CH(R³)—O—)_(l)—R⁵  (I) where the units —(—CH₂—CH(R²)—O—)_(k) and —(—CH₂—CH(R³)—O—)_(l) are arranged in block structure in the order shown in formula (I) and the radicals and indices have the following meaning: k: a number from 10 to 150, l: a number from 5 to 25, R¹: H or methyl, R²: independently of one another, H, methyl or ethyl, with the proviso that at least 50 mol % of the radicals R² are H, R³: independently of one another, a hydrocarbon radical having at least 2 carbon atoms or an ether group of the general formula —CH₂—O—R^(2′), where R^(2′) is a hydrocarbon radical having at least 2 carbon atoms, R⁴: a single bond or a divalent linking group selected from the group of —(C_(n)H_(2n))—, —O—(C_(n′)H_(2n′))— and —C(O)—O—(C_(n″)H_(2n″))—, where n, n′ and n″ is in each case a natural number from 1 to 6, R⁵: H or a hydrocarbon radical having 1 to 30 carbon atoms.
 2. The additive according to claim 1, wherein R³ is a hydrocarbon radical having at least 3 carbon atoms.
 3. The additive according to claim 1, wherein R¹ is H and R⁴ is a group selected from —CH₂— or —O—CH₂—CH₂—CH₂—CH₂—.
 4. The additive according to claim 1, wherein R⁵ is H.
 5. The additive according to claim 1, wherein at least one of the monomers (b) is a monomer comprising acid groups or salts thereof.
 6. The additive according to claim 5, wherein the acidic groups are at least one group selected from the group of —COOH, —SO₃H and —PO₃H₂ or salts thereof.
 7. The additive according to claim 1, wherein the copolymer comprises at least two different hydrophilic monomers (b), and these are at least one neutral hydrophilic monomer (b1), and at least one hydrophilic anionic monomer (b2) which comprises at least one acid group selected from the group of —COOH, —SO₃H or —PO₃H₂ or salts thereof, where the amount of the monomers (a) is 0.1 to 12% by weight and that of all the monomers (b) together is 70 to 99.5% by weight with regard to the amount of all of the monomers in the copolymer.
 8. The additive according to claim 7, wherein the neutral monomer (b1) is a monomer (meth)acrylamide, N-methyl(meth)acrylamide, N,N′-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide or N-vinyl-2-pyrrolidone, and the monomer (b2) is at least one selected from the group of (meth)acrylic acid, vinylsulfonic acid, allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 2-methacrylamido-2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonic acid, 2-acrylamido-2,4,4-trimethylpentanesulfonic acid and vinylphosphonic acid.
 9. The additive according to claim 7, wherein the copolymer further comprises at least one cationic monomer (b3) having ammonium groups.
 10. The additive according to claim 9, wherein the cationic monomer is salts of 3-trimethylammonium propyl(meth)acrylamides or 2-trimethylammonium ethyl(meth)acrylates.
 11. The additive according to claim 7, wherein the amount of the monomers (a) is 0.1 to 5% by weight with regard to the amount of all of the monomers in the copolymer.
 12. The additive according to claim 1, wherein the copolymer comprises at least two different hydrophilic monomers (b), and these are at least one neutral hydrophilic monomer (b1), and at least one cationic monomer (b3), where the amount of the monomers (a) is 0.1 to 12% by weight and that of all of the monomers (b) together is 70 to 99.9% by weight with regard to the amount of all of the monomers in the copolymer.
 13. The additive according to claim 1, wherein the copolymer comprises at least two different hydrophilic monomers (b), and these are at least 5 to 50% by weight of at least one neutral hydrophilic monomer (b1), and 25 to 94.9% by weight of at least one anionic monomer (b2) comprising sulfonic acid groups, where the amount of the monomers (a) is 0.1 to 12% by weight, and that of all of the monomers (b) together is 70 to 99.9% by weight with regard to the amount of all of the monomers in the copolymer.
 14. The additive according to claim 12, wherein the copolymer comprises, as monomer (a), additionally at least one monomer of the general formulae H₂C═C(R¹)—COO—(—CH₂—CH(R⁵)—O—)_(q)—R⁶  (IIa) and/or H₂C═C(R¹)—O—(—CH₂—CH(R⁵)—O—)_(q)—R⁶  (IIb), where R¹ is H or methyl, q is a number from 10 to 150, R⁵, independently of one another, are H, methyl or ethyl, where at least 50 mol % of the radicals R⁵ are H, and R⁶ is an aliphatic and/or aromatic, straight-chain or branched hydrocarbon radical having 6 to 40 carbon atoms, with the proviso that at least 0.1% by weight of the monomers (a) of the formula (I) are used, and furthermore at least 25% by weight of the amount of all of the monomers (a) are monomers of the formula (I).
 15. The additive according to claim 12, wherein the copolymer also comprises up to 1% by weight of a crosslinking monomer (d) comprising at least two ethylenically unsaturated groups, where monomer (d) is at least one selected from the group of 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate or oligoethylene glycol di(meth)acrylates such as, for example, polyethylene glycol bis(meth)acrylate, N,N′-methylenebis(meth)acrylamide, ethylene glycol divinyl ether, triethylene glycol divinyl ether, triallylamine, triallylamine methammonium chloride, tetraallylammonium chloride and tris(2-hydroxy)isocyanurate tri(meth)acrylate.
 16. A hydraulic binder system which comprises the additive as claimed in claim 1 and wherein the binder is cement, lime, gypsum or anhydrite.
 17. A nonflowable construction system which comprises the additive as claimed in claim 1 wherein the nonflowable construction system is tile adhesives, plasters or gap fillers, and flowable construction systems selected from the group of self-leveling floor screeds, sealing and repair mortars, flow screeds, flow concrete, self-compacting concrete, underwater concrete or underwater mortar.
 18. The nonflowable construction system according to claim 17, wherein the amounts of the copolymers are between 0.001 and 5% by weight, based on the dry weight of the construction system.
 19. The additive according to claim 1, wherein the copolymer is used in combination with nonionic polysaccharide derivatives selected from the group of methylcellulose (MC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), methylhydroxyethylcellulose (MHEC), methylhydroxypropylcellulose (MHPC) and also Welan gum or Diutan gum. 